Best card diagnostic solutions
  • Fast Dispatch And
    Delivery
  • Highest Quality
    Standard & Safety
  • 100% Satisfaction
    Guaranteed
  • Best Value for
    your money
  • Great Customer
    Service

Honda automatic transmission (MRPA) – hydraulic part

Honda automatic transmission (MRPA) - hydraulic part 1
1

Without keyword

Continuing the story of Honda’s MRPA gearbox. In the final part of the article we will tell about the device of the hydraulic part of the machine.

The valve block consists of a main valve block, a regulator block, and a servo block. The working fluid pump is driven by a torque converter. The working fluid through the pressure regulator (which modulates the pressure to match its set value) enters the main valve block and then to the range selection valve, where, depending on the position of the selector, it is distributed to the corresponding hydraulic valves and couplings.

Main valve block

The main valve block includes: a range selection valve, hydraulic valves A, B, C, E, a safety valve, a torque converter lockout control valve, an automatic transmission cooling system valve, a servo control valve and a working fluid pump gear. The main function of the main valve block is to control the hydraulic fluid pressure of the hydraulic control system.

Pressure regulator unit

The regulator unit includes: a regulator valve, a torque converter control valve, a torque converter lock-on valve, and first and third gear accumulators.

Honda automatic transmission (MRPA) - hydraulic part 2

Valve block 1 – servo unit, 2 – gear shifting solenoid valve “A”, 3 – gear shifting solenoid valve “D”, 4 – gear shifting solenoid valve “B”, 5 – gear shifting solenoid valve “E”, 6 – solenoid gearshift valve “C”, 7 – pressure control unit, 8 – main valve block, 9 – pressure control solenoid valve “A”, 10 – pressure control solenoid valves “B” and “C”.

Honda automatic transmission (MRPA) - hydraulic part 3

The main valve block. 1 – range selection valve, 2 – main valve body housing, 3 – gear shift hydraulic valve “A”, 4 – gear shift hydraulic valve “B”, 5 – gear shift hydraulic valve “C”, 6 – safety-
solid valve, 7 – automatic transmission cooling system valve, 8 – hydraulic blocking control valve-
transformer, 9 – hydraulic valve “E” gear shifting, 10 – servo control valve.

Honda automatic transmission (MRPA) - hydraulic part 4

Pressure Regulator Block 1 – pressure regulator,
2 – pressure regulator block case, 3 – torque converter lock-on valve,
4 – control valve of the torque converter.

Pressure regulator

The pressure regulator maintains a constant pressure of the working fluid supplied by the pump to the hydraulic system, lubrication system and torque converter. The working fluid from the pump enters through channels B and B ‘. The fluid supplied through the channel B through the hole enters the cavity A. An increase in pressure in the cavity A causes the regulator valve to shift to the right side and open the channels for the working fluid to flow to the torque converter and to the safety valve. After that, the fluid pressure decreases, and the regulator valve moves to the left. This ensures a constant (with small deviations from the average value) pressure of the working fluid in the system.

Note: valve movements “left” and “right” are shown in the figure by arrows.

The stator wheel of the torque converter is installed on the splines of the stator shaft. The stator shaft lever is in contact with the spring plate of the pressure regulator. When the vehicle is accelerated, the force arising on the stator wheel is transmitted to the stator shaft and the stator shaft lever, and the lever presses on the spring plate, and the pressing force is proportional to the force on the stator wheel. The spring is compressed and the regulator valve moves, providing an increase in pressure. The pressure increases to maximum when the force on the stator wheel is maximized..

Note: the direction of movement of the stator shaft lever is shown in the figure by the arrow.

Servo unit

The servo unit contains: a servo valve, a hydraulic shift valve “D”, hydraulic accumulators of the second, fourth and fifth gears, as well as solenoid valves A, B, C, D and E of the gear shift.

Accumulators

Hydraulic accumulators are located in the pressure regulator unit and in the servo drive unit. In the pressure regulator unit, hydraulic accumulators of the first and third gears are located. In the servo unit, the accumulators of the second, fourth and fifth gears are located.

Honda automatic transmission (MRPA) - hydraulic part 5

The operation of the pressure regulator (pressure regulation in the torque converter). 1 – stator wheel, 2 – stator-
n shaft, 3 – stator shaft lever, 4 – regulator spring plate, 5 – pressure regulator block housing, 6 – pressure regulator valve, 7 – torque converter.

Honda automatic transmission (MRPA) - hydraulic part 6

Servo unit. 1 – hydraulic valve “D” gear shifting, 2 – electromagnetic valve-
pan “B” gear shifting, 3 – electromagnet-
shift valve “A”, 4 – electric-
gear shift solenoid valve “D”,
5 – shift solenoid valve “E”, 6 – shift solenoid valve “C”-
gear shifting, 7 – servo unit housing.

Honda automatic transmission (MRPA) - hydraulic part 7
Accumulator location.
1 – fifth gear accumulator,
2 – the accumulator of the third gear,
3 – hydraulic accumulator first gear,
4 – pressure regulator unit housing,
5 – hydraulic accumulator fourth gear,
6 – servo valve / servo fork shaft,
7 – the housing of the servo unit,
8 – accumulator of the second gear.

Fluid distribution

Pressure distribution

During engine operation, the automatic transmission fluid pump also works. The automatic transmission fluid that has passed through the filter is sent to the hydraulic circuit. After that, the liquid enters the pump and is already under pressure supplied to the pressure regulator. From the pressure regulator, part of the working fluid through the valve enters the torque converter. To prevent excessive pressure increase in the torque converter, a torque converter control valve is used..

The electronic control unit monitors the status (ON or OFF) of the shift solenoid valves. When the solenoid valve is turned OFF, the flow of fluid from the pump through the range valve is blocked. When the solenoid valve is ON, fluid flows to the hydraulic shift valve. The electronic control unit also monitors the status (ON or OFF) of the pressure control solenoid valves. Pressure control solenoid valves regulate the pressure applied to the couplings, which ensures smooth switching of the latter.

Table. Highway Designation.

Channel number Trunk or element Channel number Trunk or element
1 Inner contour SB Shift Solenoid Valve “B”
3 Inner contour SC Shift Solenoid Valve “C”
3 ‘ Inner contour SD Shift Solenoid Valve “D”
4 Inner contour SE Gear Shift Solenoid “E”
4′ Inner contour 10 First gear clutch
4” Inner contour 20 Second gear clutch
7 Inner contour thirty Third gear clutch
1A Internal circuit or pressure control solenoid valve “A” 40 Fourth gear clutch
1B Inner contour fifty Fifth gear clutch
3A Inner contour 55 Pressure Control Solenoid Valve “A”
3B Inner contour 55 ‘ Pressure Control Solenoid Valve “A”
3C Inner contour 56 Pressure Control Solenoid Valve “B”
5A Inner contour 57 Pressure Control Solenoid Valve “C”
5B Inner contour 90 Torque converter
5C Inner contour 91 Torque converter
5D Inner contour 92 Torque converter
5E Internal circuit or hydraulic valve “B” pressure control 93 Fluid cooler
5F Internal circuit or hydraulic valves “A” or “B” pressure control 94 Torque converter
5g Hydraulic Pressure Control Valve “B” 95 Grease
5H Hydraulic Pressure Control Valve “C” 96 Torque converter
5J Hydraulic Pressure Control Valve “B” 97 Torque converter
5K Hydraulic Pressure Control Valve “B” 99 Fluid intake
5L Hydraulic Pressure Control Valve “B” X Drain
5N Hydraulic Pressure Control Valve “B” Hx Maximum discharge
SA Shift Solenoid Valve “A” Ax Air bleeding

Table. Solenoid Valve Status and Shifting Hydraulic Shift Valves.

Range Broadcast Solenoid Valve Status Moving hydraulic valves
A B C D E A B C D E
1 ON ON ON Off Off
2 Off ON Off ON Off
3 Off Off ON Off Off
D 4 ON Off Off Off Off
5 ON Off ON ON Off
R Reverse ON ON Off Off ON
P Off ON Off Off ON
N Neutral Off ON ON Off Off

Note: in the table, the arrows indicate the directions of movement of the hydraulic valves shown in the figure “Distribution of working fluid flows”.

Honda automatic transmission (MRPA) - hydraulic part 8

The distribution of fluid flows. 1 – torque converter, 2 – pressure sensor of the working fluid in the circuit of the third gear clutch, 3 – hydraulic accumulator of the third gear,
4 – clutch of the second gear, 5 – clutch of the first gear, 6 – hydraulic accumulator of the first gear,
7 – the hydraulic accumulator of the fourth gear, 8 – the coupling of the fourth gear, 9 – the coupling of the fifth gear, 10 – the hydraulic accumulator of the fifth gear, 11 – the hydraulic accumulator of the second gear,
12 – second gear clutch, 13 – working fluid pressure sensor in the second gear clutch, 14 – gear shifting solenoid valve “A”, 15 – gear shifting solenoid valve “B”, 16 – gear shifting solenoid valve “C”,
17 – gear shifting solenoid valve “D”, 18 – gear shifting solenoid valve “E”, 19 – pressure control solenoid valve “A”, 20 – electro-
solenoid valve “B” for pressure control, 21 – solenoid valve “C” for pressure control, 22 – servo control valve, 23 – hydraulic valve “E” for gear shifting, 24 – hydraulic valve “D” for gear shifting, 25 – hydraulic valve “C “gear shifting, 26 – hydraulic valve” B “gear shifting, 27 – hydraulic valve” A “gear shifting, 28 – torque converter lock-up valve, 29 – range selection valve, 30 – servo valve, 31 – working fluid pump, 32 – intermediate shaft, 33 – input shaft, 34 – additional spurious gear shaft, 35 – input spurious gear, 36 – output shaft, 37 – countershaft, 38 – pressure regulator, 39 – safety-
gauge valve, 40 – working fluid cooler, 41 – automatic transmission cooling system valve, 42 – torque converter lockout control valve, 43 – hydraulic control valve-
transformer.

The torque converter lock mechanism works when the selector is in position “D”, with second, third, fourth or fifth gears engaged. In the “D3” range, the lock can be engaged in second and third gears, in the “M” range in third, fourth or fifth gears. Along with the hydraulic control of the torque converter, electronic (via the control unit) is also provided, which provides the most accurate choice of the moment the lock is turned on (off).

The control unit sends a signal to the electromagnetic valve E, turning it on or off, depending on the signal, and controls (turns on or off) the hydraulic blocking valve, which opens or closes the flow of working fluid into the torque converter. The pressure control solenoid valve A and the torque converter lockout valve control the degree of torque converter lockout.

Torque converter lock on

The working fluid is drained from the cavity between the housing and the torque converter piston. The fluid enters the torque converter through the cavity between the pump and reactor wheels. The torque converter piston is connected to the torque converter housing and the torque converter is locked. The input shaft of the gearbox rotates at the same frequency as the crankshaft of the engine.

Torque converter lock off

The working fluid enters through the cavity, between the housing and the torque converter piston, passes the torque converter and exits through the cavity between the turbine and reactor wheels, as well as through the cavity between the pump and reactor wheels. The torque converter piston is not connected to the torque converter housing and the torque converter is not blocked.

Fluid distribution

Torque converter lock off

The electronic control unit turns off (OFF) the shift solenoid valve “E” and the working fluid is not supplied to the right cavity of the hydraulic valve for locking the torque converter. The valve remains in the rightmost position and the working fluid flows through the “94” line into the torque converter. The lock-up clutch is turned off, the piston is not connected to the torque converter housing and the lock is turned off.

Honda automatic transmission (MRPA) - hydraulic part 9

Torque converter lock on.

Honda automatic transmission (MRPA) - hydraulic part 10

Torque converter lock off.

Honda automatic transmission (MRPA) - hydraulic part 11
Torque converter lock off.
1 – torque converter,
2 – the electromagnetic valve “E” gear shifting,
3 – pressure control solenoid valve “A”,
4 – hydraulic valve “A” and “D” gearshift,
5 – range selection valve,
6 – working fluid pump,
7 – pressure regulator,
8 – safety valve,
9 – fluid cooler,
10 – control valve lock torque converter,
11 – automatic transmission cooling system valve,
12 – control valve torque converter,
13 – valve lock torque converter,
14 – shaft additional spurious gear,
15 – additional spurious gear,
16 – input shaft,
17 – output shaft,
18 – a leading gear wheel of the main transfer,
19 – countershaft.

Partial torque converter lock-up

When the vehicle reaches a certain speed, the control unit turns on (ON) the torque converter lock-up solenoid valve “E” and pressure fluid is supplied to the right side of the torque converter lock-up valve. The torque converter lock-up valve moves to the left and opens the “94” line. The torque converter lockup clutch engages. The pressure of the working fluid flowing to the torque converter lock-up valve and the torque converter lock-up control valve is controlled by the pressure control solenoid valve “A”. The torque converter lock-up control valve controls the amount of working fluid entering the cavity between the piston and the torque converter housing.

Honda automatic transmission (MRPA) - hydraulic part 12
Partial torque converter lock-up.
1 – torque converter,
2 – the electromagnetic valve “E” gear shifting,
3 – pressure control solenoid valve “A”,
4 – hydraulic valve “A” and “D” gearshift,
5 – range selection valve,
6 – working fluid pump,
7 – pressure regulator,
8 – safety valve,
9 – fluid cooler,
10 – control valve lock torque converter,
11 – automatic transmission cooling system valve,
12 – control valve torque converter,
13 – valve lock torque converter,
14 – shaft additional spurious gear,
15 – additional spurious gear,
16 – input shaft,
17 – output shaft,
18 – a leading gear wheel of the main transfer,
19 – countershaft.

Full torque converter lock

When the vehicle speed increases, the control unit sends a pressure increase signal to the pressure control solenoid valve “A”. The pressure in the line “55” increases and the check valve for locking the torque converter moves to the left, blocking the flow of working fluid into the torque converter along the line “94”. The torque converter lock-up clutch engages and the lock is fully engaged.

Honda automatic transmission (MRPA) - hydraulic part 13
Full torque converter lock.
1 – torque converter,
2 – the electromagnetic valve “E” gear shifting,
3 – pressure control solenoid valve “A”,
4 – hydraulic valve “A” and “D” gearshift,
5 – range selection valve,
6 – working fluid pump,
7 – pressure regulator,
8 – safety valve,
9 – fluid cooler,
10 – control valve lock torque converter,
11 – automatic transmission cooling system valve,
12 – control valve torque converter,
13 – valve lock torque converter,
14 – shaft additional spurious gear,
15 – additional spurious gear,
16 – input shaft,
17 – output shaft,
18 – a leading gear wheel of the main transfer,
19 – countershaft.

Author: Rodionov Alexander. Legion Autodata

RELATED POSTS

  • Honda automatic transmission (MRPA) - hydraulic part 14

    Honda automatic transmission (MRPA) – electronic control system

    Without keyword We continue the story about the automatic transmission MRPA. The first part of the article talked about the mechanical structure of this…

  • Honda automatic transmission (MRPA) - hydraulic part 15

    Honda automatic transmission (MRPA) – mechanical

    Without keyword The article will focus on Honda’s MRPA automatic gearbox, installed on cars such as the Honda Integra and Acura RSX. This part of the…

  • Honda automatic transmission (MRPA) - hydraulic part 16

    How to slip on automatic transmission? Driving a car – A variety of tips for motorists – Everything for a car in St. Petersburg

    How to slip on automatic transmission? 1. Allow the box to cool in case of a long passage The main sources of heat in the automatic transmission is a…

  • Honda automatic transmission (MRPA) - hydraulic part 17

    What is the main principle of automatic transmission?

    What is the principle of operation of an automatic transmission? The principle of operation of an automatic transmission is a rather complicated process…

About 1

Leave a Reply

Your email address will not be published. Required fields are marked *

© Copyright 2018 Carscanners. All rights reserved.
error

Enjoy this blog? Please spread the word :)