CN101566204A - Intermediate shaft brake of reversing valve pump control type automatic transmission - Google Patents

Abstract

The invention discloses an intermediate shaft brake of a reversing valve-controlled pump type automatic transmission, which comprises a hydraulic pump; The oil port is connected to the hydraulic pump, the oil outlet is directly connected to the oil tank, the other oil outlet is connected to the oil inlet of the constant pressure relief valve, the oil return port of the constant pressure relief valve is connected to the oil tank, and the oil inlet is connected to the two-position three-way solenoid One oil outlet of the reversing valve is connected. The beneficial effects of the present invention are: 1. While the intermediate shaft of the automatic transmission is braking, the heat generated by the energy loss can be taken away by the hydraulic oil to provide a stable and accurate braking torque; 2. There is basically no wear, and the use of Long service life, effectively reducing maintenance costs; 3. No power source is required, and the structure is simple.

Description

Reversing Valve Controlled Pump Automatic Transmission Countershaft Brake

technical field

The invention relates to a countershaft braking device of an automatic transmission, in particular to a countershaft brake of a countershaft type electromechanical automatic transmission (AMT).

Background technique

The electromechanical automatic transmission (AMT) is based on the traditional manual transmission, and its shift actuator is changed from the traditional manual control method to the electronic control method. Most of the mature manual transmissions adopt intermediate shaft-type stepped gear transmission. By changing the meshing state of the gear set and changing the transmission ratio, the purpose of speed change is achieved. When the car is promoted from low gear to high gear, the clutch is disengaged and the gear set is in neutral. At this time, the intermediate shaft is still in a state of high-speed rotation due to inertia, and its speed is higher than that of the high gear that will be meshed. cause teething. In order to reduce the impact of shifting and shorten the shifting time, the automatic transmission is equipped with a countershaft brake, which forcibly reduces the speed of the countershaft. At present, the known intermediate shaft brake adopts a commonly used wet multi-plate clutch structure, which is mainly composed of pistons, pressure plates, friction plates, solenoid valves, hydraulic pressure sources (or air pressure sources) and other components, wherein the friction plates and the intermediate shaft are connected by splines. Rotate at the same speed, but the pressure plate is restricted by the brake housing and cannot rotate. When it is necessary to brake the intermediate shaft, the transmission control unit (TCU) sends a signal to energize the solenoid valve coil, and the piston moves axially under the action of hydraulic pressure (or air pressure), so that the pressure plate and the friction plate are tightly combined, and the pressure plate and the friction plate The friction between them makes the speed of the intermediate shaft drop sharply, achieving the purpose of braking the intermediate shaft. Obviously, the above-mentioned brake has the following disadvantages: 1. The long-term operation of the friction plate will easily cause a sharp rise in temperature, thereby causing a change in the friction coefficient, affecting the braking effect, and is not conducive to programmed control; 2. The friction plate is easy to wear and tear. It needs to be replaced regularly, because the installation position is in the transmission housing, the transmission needs to be disassembled, and the maintenance cost is high; 3, the structure is complicated, and the manufacturing and installation costs are relatively high.

Contents of the invention

In order to solve the problems that the existing intermediate shaft brake is unfavorable to programmed control, maintenance, and high manufacturing and installation costs, the invention provides a reversing valve-controlled pump type automatic transmission intermediate shaft brake.

The object of the present invention is achieved in the following manner: a countershaft brake of a reversing valve-controlled pump type automatic transmission, comprising a hydraulic pump; a two-position three-way electromagnetic directional valve, the two-position three-way electromagnetic directional valve and The automatic transmission TCU is electrically connected, the oil inlet is connected to the hydraulic pump, the oil outlet is directly connected to the fuel tank, the other oil outlet is connected to the oil inlet of the constant pressure relief valve, the oil return port of the constant pressure relief valve is connected to the fuel tank, and the oil inlet The port is connected with an oil outlet of the two-position three-way solenoid valve.

The displacement of the hydraulic pump is 10-15ml/r.

The diameter of the two-position three-way electromagnetic reversing valve is 6-12mm.

The pressure value of the constant pressure relief valve is 1.5~2MPa.

The hydraulic pump, the two-position three-way electromagnetic reversing valve and the constant pressure relief valve are arranged in series, and there is a hydraulic oil passage in between.

In the present invention, a hydraulic pump is installed at the output end of the intermediate shaft of the transmission, and the intermediate shaft drives the rotor of the hydraulic pump to rotate, and the hydraulic pump is used as the braking load of the intermediate shaft; One oil outlet of the electromagnetic reversing valve is directly connected to the oil tank, the other oil outlet is connected to a constant pressure relief valve oil inlet, and the oil return port of the constant pressure relief valve is connected to the oil tank; the transmission control unit (TCU) sends a signal Control the voltage of the reversing valve coil to change the oil path at the outlet of the hydraulic pump, thereby controlling the effective time of the braking torque of the intermediate shaft. When the intermediate shaft does not need to be braked, the TCU sends a signal to control the coil voltage of the electromagnetic reversing valve to be zero, the electromagnetic reversing valve works in the "upper position", the oil at the outlet of the hydraulic pump is directly returned to the oil tank, and the pressure at the outlet of the hydraulic pump is zero. The intermediate shaft has no braking torque, and of course there is no energy loss; when the intermediate shaft needs to be braked, the TCU sends a signal to control the coil voltage of the electromagnetic reversing valve to the rated voltage value, the electromagnetic reversing valve works in the "lower position", and the hydraulic pump The outlet oil needs to pass through the constant pressure relief valve to return to the oil tank. At this time, the pressure at the outlet of the hydraulic pump is a corresponding constant value, and the braking torque is also a corresponding constant value. The speed of the intermediate shaft will drop immediately. The energization time of the valve is used to control the effective time of the braking torque to achieve the purpose of braking the intermediate shaft. The beneficial effects of the present invention are: 1. While the intermediate shaft of the automatic transmission is braking, the heat generated by the energy loss can be taken away by the hydraulic oil to provide a stable and accurate braking torque; Long service life, effectively reducing maintenance costs; 3. No power source is required, and the structure is simple.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the connection schematic diagram of the present invention and a 4-speed speed changer;

In the figure, 1. Transmission input shaft, 2. Input shaft gear, 3. First gear, 4. First and second gear combination sleeve, 5. Second gear, 6. Third gear, 7. Third and fourth gear combination sleeve , 8. Fourth gear, 9. Reverse gear, 10. Reverse gear coupling sleeve, 11. Transmission output shaft, 12. Reverse gear idler, 13. Transmission intermediate shaft, 14. Hydraulic pump, 15. Fuel tank, 16. Electromagnetic reversing valve, 17. constant pressure relief valve, 18. engine output shaft, 19. clutch.

Detailed ways

As shown in Figure 1, a reversing valve control pump type automatic transmission intermediate shaft brake includes a hydraulic pump 14; a two-position three-way electromagnetic reversing valve 16, and the two-position three-way electromagnetic reversing valve 16 is connected with the automatic transmission The TCU is electrically connected, the oil inlet is connected to the hydraulic pump 14, the oil outlet is directly connected to the fuel tank, the other oil outlet is connected to the oil inlet of the constant pressure relief valve 17, and the oil return port of the constant pressure relief valve [17] is connected to the fuel tank , the oil inlet is connected to an oil outlet of the two-position three-way electromagnetic directional valve 16; the displacement of the hydraulic pump 14 is 10-15ml/r; the diameter of the two-position three-way electromagnetic directional valve 16 is 6-12mm; The pressure value of the constant pressure relief valve 17 is 1.5-2Mpa; the hydraulic pump 14, the two-position three-way electromagnetic reversing valve 16 and the constant pressure relief valve 17 are arranged in series, and there is a hydraulic oil passage in between.

As shown in Figure 2, a 4-speed transmission includes a transmission input shaft 1, an input shaft gear 2, a first gear 3, a combination sleeve 4 for first and second gears, a 5 gear for second gear, a gear 6 for third gear, and a combination sleeve 7 for third and fourth gears. , fourth gear 8, reverse gear 9, reverse gear coupling sleeve 10, transmission output shaft 11, reverse gear idler 12, transmission intermediate shaft 13 Step up into the second gear as an example), at first, the clutch 19 is separated, and the power transmission between the engine output shaft 18 and the transmission input shaft 1 is interrupted; In the neutral position, the power transmission between the transmission intermediate shaft 13 and the transmission output shaft 11 is interrupted. The next action is to move the first and second gear combination sleeve 4 to the right again, and combine it with the second gear 5, so that the transmission intermediate shaft 13 and the transmission output shaft 11 transmit power through the second gear 5. During this process, due to the inertia, the intermediate shaft 13 of the transmission still maintains the rotational speed when the first gear is combined after entering the neutral gear, that is, the second gear 5 also maintains the corresponding rotational speed; also affected by the inertia, the first and second gears Combining sleeve 4 keeps the corresponding rotating speed when the first gear is combined. Obviously, due to the difference in speed ratio between the gear pairs, the rotational speed of the second gear 5 is higher than that of the first and second gear coupling sleeves 4. In order not to cause shifting impact and prolong the service life of the gears, it is desired that the rotational speeds of the two be synchronized. In order to synchronize the rotational speeds of the two, it is necessary to brake the intermediate shaft 13 of the transmission. After calculation, the braking torque is ideally 40-60 N.m.

The present invention utilizes a hydraulic oil pump 14, an electromagnetic reversing valve 16 and a constant pressure relief valve 17 to provide braking torque for the transmission intermediate shaft 13, and splines and flat keys can be used between the hydraulic oil pump 14 and the transmission intermediate shaft 13 or flanges and other forms of connection, the intermediate shaft 13 drives the rotor of the hydraulic oil pump 14 to rotate synchronously, and the oil is pumped out. The oil outlet of the hydraulic oil pump 14 is connected to the inlet of the electromagnetic reversing valve 16, one oil outlet of the electromagnetic reversing valve 16 is directly connected to the oil tank, and the other oil outlet is connected to the oil inlet of the constant pressure relief valve 17, and the constant pressure overflow The valve 17 is connected to the oil tank 15 at the oil return port. Obviously, when the electromagnetic reversing valve 16 works in the "upper position", the oil at the outlet of the hydraulic pump 14 is directly returned to the oil tank through the valve, the pressure of the hydraulic oil is extremely low, and the driving torque required by the hydraulic pump 14 is basically zero. As far as shaft 13 is concerned, the braking torque received is also close to zero; when electromagnetic reversing valve 16 works in the "lower position", the oil at the outlet of hydraulic pump 14 can only return to the oil tank through constant pressure relief valve 17, due to constant pressure Due to the function of the relief valve 17, the outlet oil pressure of the hydraulic pump 14 will maintain a constant value, and the driving torque required by the hydraulic pump 14 will also be a constant value. For the intermediate shaft 13 of the transmission, the received braking torque will also maintain a fixed value. Therefore, when there is no need to brake the intermediate shaft 13, it is only necessary to control the electromagnetic reversing valve 16 through the TCU so that the valve works in the "upper position" and reduce the outlet oil pressure of the hydraulic pump 14 to zero; , through the TCU to control the electromagnetic reversing valve 16, so that the valve works in the "lower position", keep the outlet oil pressure of the hydraulic pump 14 at a fixed value, and adjust its action time according to the braking requirements. After calculation, to provide an ideal braking torque of 40-60N.m, only one ordinary hydraulic oil pump with a displacement of 10-15ml, one ordinary two-position three-way electromagnetic reversing valve with a diameter of 6-12mm, and one with a pressure of 1.5 An ordinary overflow valve of ~2MPa is enough; at the same time, the heat generated during the braking process is taken away by the hydraulic oil in real time, without any cooling device. The invention is easy to realize, simple in structure and low in cost.

Claims (5)

1. A countershaft brake for a valve-controlled pump-type automatic transmission, characterized in that it includes a hydraulic pump [14]; a two-position three-way electromagnetic directional valve [16], and the two-position three-way electromagnetic directional valve [16] is electrically connected to the TCU of the automatic transmission, the oil inlet is connected to the hydraulic pump [14], the oil outlet is directly connected to the fuel tank, and the other oil outlet is connected to the oil inlet of the constant pressure relief valve [17] for constant pressure relief The oil return port of valve [17] is connected to the oil tank, and the oil inlet links to each other with an oil outlet of the two-position three-way electromagnetic directional control valve [16]. 2. The countershaft brake of a reversing valve-controlled pump type automatic transmission according to claim 1, characterized in that: the displacement of the hydraulic pump [14] is 10-15ml/r. 3. The countershaft brake of a reversing valve-controlled pump type automatic transmission according to claim 1, characterized in that the diameter of the two-position three-way electromagnetic reversing valve [16] is 6-12 mm. 4. The intermediate shaft brake of a reversing valve-controlled pump type automatic transmission according to claim 1, wherein the pressure value of the constant pressure relief valve [17] is 1.5-2 MPa. 5. A countershaft brake for a reversing valve-controlled pump type automatic transmission according to claim 1, characterized in that: a hydraulic pump [14], a two-position three-way electromagnetic reversing valve [16] and a constant pressure relief valve [17] Set in series with hydraulic oil passages in between.

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