Electropneumatic transmission adjuster

Abstract

The invention relates to an electropneumatic transmission regulator (1) for shifting an automated gearshift transmission (19) in a commercial vehicle, the transmission regulator comprising: a compressed air supply system (5), an arrangement consisting of a pneumatic shift cylinder (15) and associated electrical shift valves (13, 14) installed in a transmission regulator housing (2) which is as closed as possible, wherein the shift cylinder (15) can be pneumatically actuated via the compressed air supply system (5) of the vehicle by means of the shift valves (13, 14), and the transmission regulator has a pressure reducing valve (3) by means of which the supply pressure provided by the compressed air supply system (5) can be limited to a shift pressure intended for actuating the shift cylinder (15), wherein the pressure reducing valve (3) is completely integrated into the transmission regulator housing (2) without protruding laterally from the transmission regulator housing or being attached to the transmission regulator housing.

Description

Technical Field

[0001] The invention relates to an electropneumatic transmission controller for shifting an automated gearshift transmission in a commercial vehicle, the transmission controller having a compressed air supply system and having an arrangement consisting of a pneumatic shift cylinder and an electrical shift valve associated with the pneumatic shift cylinder, which is installed in a transmission controller housing that is as closed as possible, wherein the shift cylinder can be pneumatically actuated via the compressed air supply system of the vehicle by means of the shift valve, and the transmission controller also has a pressure reducing valve by means of which the supply pressure provided by the compressed air supply system can be limited to a shift pressure intended for actuating the shift cylinder. Background Art

[0002] Transmission controllers are used for automating the shifting in and out of gears in manual transmissions in motor vehicle drive trains and are known in various embodiments.

[0003] Pneumatic automatic transmissions in commercial vehicles are often designed in a group structure, with a main transmission, an upstream transfer transmission and a downstream selector transmission, wherein the transfer transmission and the selector transmission are each assigned a pneumatic shift cylinder for changing between two transmission stages, and the main transmission is assigned one or more shift cylinders for selecting gears and, if necessary, for selecting a shift path. Two shift valves designed as electrically controllable solenoid valves are assigned to each of the shift cylinders. The arrangement consisting of the shift cylinders and the shift valves is installed in a common housing and, together with an integrated electronic control unit, forms a so-called transmission controller of such a transmission.

[0004] Pneumatic switching cylinders are usually designed as piston-cylinder devices, in which a linearly movable piston rod carries a double-acting piston at the end, which separates two pressure chambers from each other in a sealed manner. The piston is supplied with compressed air, which flows into one of the two pressure chambers in a valve-controlled manner, depending on the intended direction of movement, while exhausting the other pressure chamber. The piston rod also has an interface outside the cylinder for transmitting the adjustment force to the shifting element of the transmission. The application of compressed air to the piston via the pressure chamber and the exhaust of the pressure chamber are controlled by a switching valve, wherein each pressure chamber is usually assigned a switching valve, which opens or closes the pressure line connected to it.

[0005] The compressed air required for actuating the switching cylinders is usually provided by a compressed air supply system of the vehicle, to which a plurality of compressed air circuits for other pneumatic consumers, such as the brake system, level control system, etc., are connected.

[0006] It has been found that the air supply pressure provided for the piston rod to move back and forth in the shifting cylinder is often higher than the required switching pressure. This can overload the moving parts. In particular, this can cause shift jerks and loud shift noises and ultimately damage the transmission. A pressure reducing valve is therefore often provided upstream of the transmission regulator in the area of ​​the compressed air supply line in order to reduce the supply pressure directly to the shifting transmission to the required level. This pressure reducing valve is usually flange-connected to the housing of the transmission regulator as a separate component and projects laterally from the housing.

[0007] Figure 3 For example, according to the WABCO publication 815 020 266 3 / 08.2020 “WABCO Automatisiertes Schaltgetriebe (AMT), Aftermarket- A perspective view of such a transmission controller 1.1 according to the prior art, known from the "Automated Transmission (AMT) from ZF", is shown in the "Automated Transmission (AMT) from WABCO, aftermarket solution for transmission control of ZF transmissions". The transmission controller 1.1 has a closed transmission controller housing 2.1, to which a pressure reducing valve 3.1 is flange-connected. The pressure reducing valve 3.1 is installed as a separate component in a separate pressure reducing valve housing 4.1.

[0008] Figure 4 Show according to Figure 3 Schematic simplified circuit diagram of such a known transmission regulator 1.1. Thus, a compressed air supply system 5 of a commercial vehicle has a compressor 6 which can be driven by a drive motor (not shown). Ambient air is compressed in the compressor 6 and is delivered to a multi-circuit protection valve 8 via a first pressure line 7 and an air cleaner and an air dryer (not shown). The compressed air circuit 9 of the transmission regulator 1.1 and other compressed air circuits 10a, 10b, 10c for other consumers, which are only shown here, are connected to the multi-circuit protection valve 8. The multi-circuit protection valve 8 has the function of transferring the compressed air present at the output of the compressor 6 independently of each other to the compressed air circuits 9, 10a, 10b, 10c of the consumers and automatically disconnecting the pressure circuits from the compressed air supply in the event of failure or leakage of the pressure circuits.

[0009] The output of the multi-circuit protection valve 8 to the transmission regulator compressed air circuit 9 is pneumatically connected to the input of the pressure reducing valve 3.1 via a second pressure line 11. The transmission regulator compressed air circuit 9 has a plurality of pneumatic shifting cylinders and shifting valves assigned thereto. Figure 4Only the switching cylinder 15 and the two associated switching valves 13, 14 are shown as examples. The switching cylinder 15 is designed as a double-acting piston-cylinder arrangement. The switching valves 13, 14 are electrically actuated 3 / 2-way valves. The pressure reducing valve 3.1 is pneumatically connected on the output side to the input of the first switching valve 13 and to the input of the second switching valve 14 via the third pressure line 12. Other switching valves (not shown) of other switching cylinders are connected to this pressure line 12.

[0010] The first switching valve 13 is connected on the output side to a first pressure chamber 16 of the switching cylinder 15. The second switching valve 14 is connected on the output side to a second pressure chamber 17 of the switching cylinder 15. By means of the intake and exhaust of the two pressure chambers 16, 17, the piston 18 of the switching cylinder 15 can be moved linearly in order to load or unload the shifting element (not shown) of the only schematically illustrated automatic gearshift transmission 19 with the actuating force. The pressure reducing valve 3.1 can be set in this case so that the supply pressure on the input side is reduced on the output side to a predetermined maximum switching pressure, so that a reduced pressure is always present at the input of the switching valves 13, 14.

[0011] Such a transmission adjuster 1.1 has proven to be advantageous many times. However, the disadvantage is that the pressure reducing valve 3.1, which is flange-connected to the transmission adjuster housing 2.1, prevents a flat and coordinated design of the transmission adjuster and increases the required installation space. Due to the flange-connected pressure reducing valve 3.1, the transmission adjuster 1.1 is loaded via an external lever arm, which includes movable masses. This also increases the vibration and impact loads to which the transmission adjuster housing 2.1 is subjected anyway due to the moving masses of the switching cylinder 15 and the switching valves 13, 14.

[0012] Furthermore, a device for controlling a double-acting hydraulic switching cylinder is known from WO 2013 110 302 A1, wherein the switching valve is accordingly designed with an integrated pressure limiting valve, wherein between a first valve position of the switching valve, which is closed relative to the pressure supply line of the hydraulic pump, and a second valve position of the valve, which is open, a third valve position is provided, in which the pressure supply line is connected to the return and the switching valve is connected to the working chamber of the respective switching cylinder. Possible valve damage due to excessive pressure should be avoided under all operating conditions.

[0013] The disadvantage is that such a pressure limiting function is practical in a transmission controller with its own hydraulic circuit, but not in a transmission controller which is installed in a compressed air supply system with a large number of consumers. Such a pressure limiting would lead to permanent, undesirable control interventions of the multi-circuit protection valve. Summary of the invention

[0014] Against this background, the object of the present invention is to specify an improved transmission adjuster with a pressure reducing valve of the aforementioned type, which transmission adjuster saves structural space and is easy to assemble, which transmission adjuster also reduces vibration and impact loads caused by the moving masses of the components of the transmission adjuster and which can also be manufactured inexpensively.

[0015] This object is achieved by an electropneumatic transmission controller having the features of claim 1. Advantageous embodiments and developments of the invention are described in the further claims.

[0016] The invention therefore relates to an electropneumatic transmission controller for shifting an automated manual transmission in a commercial vehicle, the transmission controller having a compressed air supply system and having an arrangement consisting of a pneumatic shift cylinder and an electrical shift valve associated with the pneumatic shift cylinder, which is installed in a transmission controller housing that is as closed as possible, wherein the shift cylinder can be pneumatically actuated by means of the compressed air supply system of the vehicle, and the transmission controller also has a pressure reducing valve, by means of which the supply pressure provided by the compressed air supply system can be limited to a shift pressure intended for actuating the shift cylinder.

[0017] In order to solve the problem posed, it is provided that the pressure reducing valve is completely integrated into the transmission adjuster housing without protruding laterally therefrom or being attached to the transmission adjuster housing.

[0018] The invention solves the described technical problem in a surprisingly simple manner in that the pressure reducing valve is integrated into the transmission regulator housing, preferably into the existing free space. The orientation within the housing (i.e. horizontal or vertical orientation) can be freely selected. If necessary, the dimensions of the transmission regulator housing can be slightly adjusted without changing the flat design of the housing in a way that increases the structural space. The transmission regulator is thus designed with the additional function of reducing pressure without visibly changing the shape of the transmission regulator housing. Since the integrated pressure reducing valve according to the invention does not require its own housing, weight and structural space are saved compared to a pressure reducing valve that is externally flanged to the housing. The omission of the pressure reducing valve's own housing and the omission of external fixings also simplify the manufacture of the transmission regulator and reduce the manufacturing costs.

[0019] Integration into the transmission actuator housing also simplifies the internal compressed air supply to the switching valves, since the central supply pressure line of the pressure reducing valve inside the housing is more accessible to the switching valves arranged there. This is particularly advantageous for multi-speed manual transmissions (e.g. for commercial vehicles) with three or four switching cylinders and six or eight switching valves in a grouped arrangement for switching up to 16 gears.

[0020] In addition, the integrated pressure reducing valve has a favorable effect on vibration and impact loads caused by the moving masses within the transmission adjuster housing. Finally, an unintentional manual change of the pressure setting at the pressure reducing valve when operating the transmission adjuster is eliminated.

[0021] According to a further development of the invention, it can be provided that the switching pressure at the pressure reducing valve for actuating the switching cylinder can be freely set between a lower limit value and an upper limit value. This allows the transmission controller to be flexibly and very accurately adapted to different predetermined maximum permissible switching pressures for different designs and embodiments of automated manual transmissions.

[0022] Finally, the invention also relates to an automated manual transmission with an electropneumatic transmission controller for gear shifting, which is designed according to the technical features described in the claims. In addition, protection is claimed for a commercial vehicle with an automated manual transmission, a compressed air supply system and an electropneumatic transmission controller according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0024] Figure 1 A perspective view showing a transmission adjuster according to the invention,

[0025] Figure 2 Show according to Figure 1 A schematic simplified circuit diagram of such a transmission regulator,

[0026] Figure 3 A perspective view showing the aforementioned transmission adjuster according to the prior art, and

[0027] Figure 4 Show according to Figure 3 Schematic simplified circuit diagram of a known transmission regulator. Specific implementation plan

[0028] Figure 3 and Figure 4 The transmission controller 1.1 shown, which is known from the prior art, has been described above. Figure 1 and Figure 2 The transmission adjuster 1 according to the invention shown has a transmission adjuster housing 2 and a pressure reducing valve 3 in an integrated housing arrangement. For this purpose, the pressure reducing valve 3 is completely integrated into the transmission adjuster housing 2 and is not visible from the outside. As a result, there is no valve component that is externally flanged to the transmission adjuster housing. The transmission adjuster housing 2 according to the invention thus has a space-saving, circumferentially coordinated and flat, as symmetrical as possible external design, without arms or the like protruding from the transmission adjuster housing. Figure 2 The shifting arrangement of the transmission controller 2 shown corresponds as closely as possible to the Figure 4 Known gear shifting facilities.

[0029] The integrated pressure reducing valve 3 according to the invention can be set such that the supply pressure on the input side is reduced on the output side to a predetermined, required and gentle switching pressure for the shifting elements of the automated manual transmission 19 , so that a pressure higher than the required switching pressure never occurs at the input of the switching valves 13 , 14 .

[0030] List of reference numerals (part of the description)

[0031] 1 Electropneumatic transmission adjuster

[0032] 1.1 Electropneumatic transmission regulator (prior art)

[0033] 2 Transmission adjuster housing

[0034] 2.1 Transmission Regulator Housing (Prior Art)

[0035] 3 Pressure reducing valve

[0036] 3.1 Pressure reducing valve (existing technology)

[0037] 4.1 Pressure reducing valve housing (existing technology)

[0038] 5 Compressed air supply system

[0039] 6 Compressor

[0040] 7 First pressure line

[0041] 8 Multi-circuit protection valve

[0042] 9 Compressed air circuit for transmission regulator

[0043] 10a, 10b, 10c Compressed air circuit for other consumers

[0044] 11 Second pressure line

[0045] 12 Third pressure line

[0046] 13 First switching valve

[0047] 14 Second switching valve

[0048] 15 Switching cylinder, piston-cylinder facilities

[0049] 16 First pressure chamber of the switching cylinder

[0050] 17 Second pressure chamber of the switching cylinder

[0051] 18 Piston of the switching cylinder

[0052] 19 Automatic gear shift transmission

Claims

1. An electropneumatic transmission controller (1) for shifting an automated manual transmission (19) in a commercial vehicle, the transmission controller having a compressed air supply system (5), The transmission regulator has a device consisting of a pneumatic shifting cylinder (15) and an electrical shifting valve (13, 14) assigned to the pneumatic shifting cylinder, which is installed in a transmission regulator housing (2) that is as closed as possible, -in, The switching cylinder (15) can be pneumatically actuated by means of the switching valves (13, 14) via a compressed air supply system (5) of the vehicle. - the transmission controller has a pressure reducing valve (3), by means of which the supply pressure provided by the compressed air supply system (5) can be limited to a switching pressure intended for actuating the switching cylinder (15), It is characterized in that The pressure reducing valve (3) is completely integrated into the transmission adjuster housing (2) without protruding laterally from the transmission adjuster housing or being attached to the transmission adjuster housing.

2. The transmission adjuster according to claim 1, characterized in that: The switching pressure at the pressure reducing valve (3) for actuating the switching cylinder (15) can be freely set between a lower limit value and an upper limit value.

3. An automated manual transmission (19) having an electropneumatic transmission controller (1) for gear shifting, the transmission controller being designed according to one of the product claims.

4. A commercial vehicle having an automated manual transmission (19), a compressed air supply system (5) and an electropneumatic transmission controller (1) which is used for shifting the manual transmission (19) and is designed according to one of the product claims.

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