CN111089163B

CN111089163B - Hydraulic gearbox actuator

Info

Publication number: CN111089163B
Application number: CN201910957287.XA
Authority: CN
Inventors: W.赫布纳
Original assignee: FTE Automotive GmbH
Current assignee: FTE Automotive GmbH
Priority date: 2018-10-24
Filing date: 2019-10-10
Publication date: 2023-01-17
Anticipated expiration: 2039-10-10
Also published as: DE102018126550B4; KR20200047337A; KR102784461B1; CN111089163A; DE102018126550A1

Abstract

The invention relates to a hydraulic transmission actuator (10) having a support part (12), a reservoir (14) for hydraulic fluid mounted on the support part, a first hydraulic pump (16) mounted on the support part (12) and having two pressure outlets (38), and a second hydraulic pump (18) also mounted on the support part (12) and having two outlets (50) for supplying transmission operating cylinders, a proportional valve (44) being assigned to each pressure outlet (38).

Description

Hydraulic gearbox actuator

Technical Field

The present invention relates to a hydraulic transmission actuator adapted to displace (shifting) various components of a multiple ratio transmission used in a motor vehicle.

Background

The prior art includes dual clutch transmissions having two friction clutches, one assigned to even numbered gears and one assigned to odd numbered gears. By suitable actuation of the two friction clutches, a shift from one gear to the next can be made without interrupting the traction operation.

With such gearboxes, it is also known practice to displace the individual gears in the desired manner using hydraulically operated cylinders, i.e. to connect the free pinions of the gear pairs forming a transmission stage to the transmission shaft rotating in conjunction therewith and to release the connection again.

For the actuation of two friction clutches, the prior art generally makes use of clutch actuators, the essential components of which are a hydraulic pump and at least two proportional valves, by means of which a desired hydraulic pressure can be achieved under open-loop or closed-loop control. For actuating the operating cylinder, a closed hydraulic circuit can be utilized, in which the pump is arranged. Depending on the direction of rotation of the pump, a particular operating cylinder is actuated in one direction or the other.

Disclosure of Invention

The aim of the invention is to reduce the expenditure for setting the hydraulic pressure or flow of the individual components.

To achieve this object, the invention provides a hydraulic gearbox actuator having a support member, a reservoir for hydraulic fluid mounted on the support member, a hydraulic clutch pump mounted on the support member and having two pressure outlets, a proportional valve being assigned to each pressure outlet, and a hydraulic transfer pump also mounted on the support member and having two outlets for supplying gearbox operating cylinders. The invention is based on the basic idea of combining two different pumps with each other by mounting them on a support member, with the result that they can share a reservoir and, overall, obtain a very compact construction.

According to one embodiment of the invention, it is conceivable that the two pressure outlets of the hydraulic clutch pump are symmetrical with respect to each other. Here, "symmetrical with respect to each other" means that they have the same design, since they are supplied with the same hydraulic flow during operation of the pump. Thus, the two friction clutches of the dual clutch gearbox can be actuated independently of each other by the same hydraulic pump and the two proportional valves.

According to one embodiment of the invention, it is conceivable that two proportional valves are arranged in the reservoir. This makes it possible to cool them by means of the hydraulic fluid present in the reservoir.

In this case, there is preferably a flow of hydraulic fluid around the proportional valve, resulting in very good reproducibility of the damping behavior for the magnetic core.

According to one embodiment of the invention, it is conceivable that a non-return valve is arranged between the pressure outlet and the proportional valve. The check valve makes it possible to maintain a build up of hydraulic pressure at the pressure port of the gearbox actuator even if the hydraulic clutch pump is switched off.

The hydraulic clutch pump draws from the reservoir, wherein the outlet of the proportional valve leaks directly back to the reservoir. This results in a compact construction.

According to a preferred embodiment of the invention, the hydraulic clutch pump is a roller unit pump. It is remarkable in that it has a long service life with high reliability and has good delivery rates.

According to the invention, a make-up port, which is connected to the reservoir and has a one-way valve, may be provided between each outlet of the hydraulic transfer pump and the supply port for operating the cylinder. As soon as the pressure on the respective suction side is below a certain value, additional hydraulic fluid can be sucked in each case by the hydraulic circuit, which is put under pressure in one direction or the other by the hydraulic transfer pump, through the supply port. Thereby any leakage is immediately compensated.

According to an alternative embodiment of the invention, it is conceivable that the supply port for the further clutch is connected to the outlet of the hydraulic displacement pump. The further clutch may be a clutch by means of which, for example, an internal combustion engine of the hybrid drive train can be disconnected and reconnected to the gearbox. By means of the inventive gearbox actuator, the clutch can then be actuated without additional large pins.

Preferably, provision can be made here for the selector valve, the non-return valve and the proportional valve to be arranged between the outlet opening and the supply opening. By means of the selector valve, the supply port for the other clutch can be isolated from the circuit of the hydraulic transfer pump, thereby ensuring that the clutch is not accidentally supplied with pressure when the operating cylinder is actuated. It is also possible that the selector valve and the one-way valve are combined into a single component. In order to operate the supply port for the other pump, the selector valve is switched to the through-flow position, with the result that the pressure generated by the hydraulic transfer pump can then be controlled open-loop or closed-loop via the proportional valve.

Drawings

The invention will now be described by means of two embodiments, which are shown in the attached drawings. In the drawings:

FIG. 1 illustrates in perspective view a transmission actuator according to the present invention;

FIG. 2 illustrates a plan view of the transmission actuator of FIG. 1;

FIG. 3 illustrates a side view of the transmission actuator of FIG. 1;

FIG. 4 shows a cross-sectional view along the plane IV-IV of FIG. 2;

FIG. 5 shows a hydraulic circuit diagram of the transmission actuator of FIGS. 1-4; and

fig. 6 shows a hydraulic circuit diagram of a gearbox actuator according to a second embodiment.

Detailed Description

Fig. 1 to 4 show a hydraulic gearbox actuator having a central support member 12 on one side (in this case the upper side) of which a reservoir 14 for hydraulic fluid is mounted.

On opposite sides of the reservoir, first and second hydraulic pumps are mounted on the support member, these being shown below as a hydraulic clutch pump 16 and a hydraulic transfer pump 18 in order to better distinguish them.

The hydraulic clutch pump 16 is provided for providing hydraulic pressure and flow to two pressure ports 20, 22 (see also fig. 5). One of the

pressure ports

20, 22 is connected to an actuating cylinder of the first friction clutch and the other of the

pressure ports

20, 22 is connected to another actuating cylinder for the second friction clutch. The two friction clutches are part of a dual clutch transmission and are used to transmit drive torque to the first and second transmission shafts.

A hydraulic transfer pump is provided in the fluid circuit having two ports 24, 25 to which respective transfer cylinders S1 to S5 (see fig. 5) are connected. For details of these transfer cylinders reference is made to DE 10 2013 000 157 B3.

The hydraulic clutch pump is a roller cell pump and has an electric motor 30 that drives a rotor 32 that rotates in a stator 34. The stator has a fluid inlet 36 (not shown in fig. 4) via which fluid is drawn from the reservoir 14, and two pressure outlets 38.

The pressure outlet 38 is connected to outlet chambers 40 arranged on both sides of the stator 34, with the result that the axial flow path out of the respective chambers of the roller unit pump is very short.

A non-return valve 42 and a proportional valve 44 are arranged in each case between the pressure outlet 38 of the hydraulic clutch pump 16 and the

respective pressure port

20, 22. Open loop control (or closed loop control if pressure sensors are present) over the hydraulic pressure and flow of the

pressure ports

20, 22 is possible through the proportional valve 44. The check valve 42 is used to maintain pressure at the

pressure ports

20, 22 even if the hydraulic clutch pump 16 is turned off.

One particular feature of the proportional valves 44 is that they are disposed in the reservoir 14 (see in particular fig. 2). In this case, not only does the hydraulic fluid flow around them on their outer side, but it is also present in the gap between the armature and the coil of the proportional valve. This results in a very constant attenuation.

The hydraulic transfer pump 18 has a functionally identical construction to the hydraulic clutch pump 16. Also, the roller cell pump has two outlets 50 of symmetrical configuration. The difference with respect to the hydraulic clutch pump 16 is that the hydraulic transfer pump 18 can be operated in both rotational directions, whereas the hydraulic clutch pump always operates in the same transmission direction. Furthermore, the hydraulic transfer pump 18 does not primarily draw fluid from the reservoir 14, but rather, depending on the direction of rotation, from one or the other outlet 50, which correspondingly becomes the inlet. In other words, the hydraulic transfer pump 18 "pushes" hydraulic fluid either towards one port 24 or towards the other port 26, and one side or the other of the selector valves S1 to S5 is put under pressure, respectively.

Disposed between each outlet 50 of the hydraulic transfer pump 18 and the

respective port

24, 26 is a makeup port 52, the makeup port 52 being provided with a one-way valve 54, and additional hydraulic fluid can be drawn from the reservoir 14 via the makeup port 52 if the pressure on the "suction side" of the hydraulic transfer pump 18 falls below a certain value.

By means of the described gearbox actuator, it is possible to displace both friction clutches of a dual clutch gearbox simultaneously via the

pressure ports

20, 22, while the operating cylinders of the gearbox can be actuated simultaneously via the

ports

24, 26.

A second embodiment of the gearbox actuator 10 is shown in fig. 6. The same reference numerals are used for the components known from the first embodiment, and the above explanation may be focused on for this purpose.

The difference between the first and second embodiments is that in the second embodiment, a supply 27 for a further final control element is additionally provided.

The further final control element may be a parking brake. It is also possible that the further final control element is a further clutch. This further clutch can be used, for example, to disconnect and reconnect a hybrid internal combustion engine from a gearbox. The second hydraulic pump 18 in the second embodiment is continuously referred to as a hydraulic transfer pump, regardless of whether it is no longer dedicated to supplying the operating cylinders.

The supply port 27 branches off from one of the outlets 50 of the hydraulic transfer pump 18. A selector valve 60 (movable between a flow-through position and a closed position), a one-way valve 62 and a proportional valve 64 are disposed between the outlet port 50 and the supply port 27.

The selector valve 60 serves to separate the supply port 27 from the hydraulic circuit that can supply the operating cylinders. In the closed state, the presence of the supply port 27 has no effect on the operation of the hydraulic transfer pump and the supply to the operating cylinder.

If the supply port 27 is to be used, the selector valve 60 is switched to the through-flow position, and the outlet port 50, to which the supply port 27 is connected (the outlet port 50 on the right in fig. 6), is put under pressure. By activating the proportional valve, the pressure of the supply port 27 can then be controlled open loop (and closed loop if a pressure sensor is present) in a desired manner.

Claims

1. A hydraulic transmission actuator comprising a support member, a reservoir for hydraulic fluid mounted on the support member, a first hydraulic pump mounted on the support member and having two pressure outlets, and a second hydraulic pump also mounted on the support member and having two outlets for supplying transmission operating cylinders, a first proportional valve being assigned to each pressure outlet of the first hydraulic pump.

2. The hydrostatic gearbox actuator of claim 1, wherein the two pressure outlets of the first hydraulic pump are symmetrical with respect to each other.

3. The hydrostatic gearbox actuator of claim 1 or 2, wherein two of the first proportional valves are arranged in the reservoir.

4. The hydrostatic transmission actuator of claim 3, wherein there is a flow of hydraulic fluid around the first proportional valve.

5. The hydrostatic transmission actuator of claim 1, wherein the first one-way valve is disposed between the pressure outlet and the first proportional valve.

6. The hydraulic transmission actuator of claim 1, wherein the first hydraulic pump draws from the reservoir.

7. The hydraulic transmission actuator of claim 1, wherein the first hydraulic pump is a roller cell pump.

8. The hydrostatic transmission actuator of claim 1, wherein a makeup port is connected to the reservoir and has a second one-way valve, the makeup port being disposed between each outlet of the second hydraulic pump and the port for operating the cylinder.

9. The hydraulic transmission actuator of claim 1, wherein the supply port for the further clutch is connected to the outlet of the second hydraulic pump.

10. The hydraulic gearbox actuator according to claim 9, characterised in that a selector valve, a third one-way valve and a second proportional valve are arranged between the outlet of the second hydraulic pump and the supply port for the further clutch.

11. The hydraulic transmission actuator of claim 10, wherein the third one-way valve and the selector valve are combined as a single component.