GB2110777A - Automatic or manual control of vehicle transmission - Google Patents

Abstract

A power transmission apparatus for vehicles comprises a fluid pressure system controlled by electrical switches responsive to vehicle speed and including cylinder C3 for operating the clutch 109 and cylinders C1, C2 for moving the gear lever forwards, backwards, left and right to change gear automatically. Alternatively, such as on failure of the automatic system, the gear lever can be operated manually. A throttle member 105 is moved to partially close the vehicle engine throttle while the clutch is disengaged, by means of a cylinder C4. Shift to a lower ratio also occurs automatically on depression of brake pedal 122. The various cylinders are supplied with air from a compressor 101 and tank 102 via a main valve CV, microswitch operated valves MV1, MV2 actuated by a clutch-operating member 112, and four gear changing valves FV, BV, RV and LV. <IMAGE>

Description

SPECIFICATION Improvements in power transmission apparatus This invention relates to power transmission apparatus which can be controlled and automatically and is especially suitable for a motor-car.

Modern automatic transmission apparatus of no clutch pedal type incorporate a pump and turbine. This kind of transmission apparatus is very complicated. Besides, in comparison with the hand operated gear change, the automatic apparatus of no clutch pedal type will consume more than 1 5% of the fuel.

Furthermore, the automatic apparatus of no clutch pedal type must have a radiator. If the electric capacity of the battery is not enough for the car to start, the car cannot be started by pushing it forward. Also, when driving, the driver still has to operate a control lever.

When the automatic control is out of order, the car cannot be driven by using the hand gear change.

It is an object of the invention to provide a power transmission apparatus in which gear change can be operated either manually or automatically, and which does not have the disadvantages that the known automatic apparatus have as mentioned above.

According to the present invention I provide a power transmissiion apparatus comprising a gear change member, gear change means for driving the gear change member forwards and backwards, gear change means for driving the gear change member to the right and left, a clutch including a clutch engaging and disengaging member, automatic clutch member operating means, manual clutch member operating means, an automatic gear change control device, a main fluid pressure valve controlled by said control device, four fluid pressure electrically controlled gear change valves for actuating said gear change means and controlled by said control device, a pair of micro switch operated valves controlling said gear change valves and operated by the clutch engaging and disengaging member; said main valve also being controlled by said micro switch valves, to provide fluid pressure from the main valve through the micro switch valves to the gear change valves; said main valve also passing fluid pressure to said gear change means.

In carrying out the present invention, the car still has a clutch and a hand operated gear lever; therefore, this system comprises two parts: one is an automatic gear change means and the other is a manual gear change. If the part of automatic gear change means is out of order, the car still can be driven by manual change.

Because there is still a clutch in the system of the invention, the output power from the engine will be transmitted completely to the wheels. The position of the gear change lever is controlled by a control "brain", at any speed, this position will be in the right position equivalent to the speed of the car.

The invention will be further described by way of example with reference to the accompanying diagrammatic drawings wherein: Figure 1 is a block diagram of a power transmission apparatus made in accordance with the invention.

Figure 2 shows the mechanical part of the apparatus.

Figure 3 shows the electrical part of the apparatus.

Figure 4 shows a practical example of the structure of a cylinder which is put on to the floor type gear change lever of the apparatus.

Figure 5 shows a practical example of the structure of a cylinder which is used to drive the gear change lever on the steering wheel.

With reference to Fig. 1, the gear change system of the present invention comprises mainly a power source A, an automatic control device ("brain") B, a common valve C, one set of mechanical valves D, one set of control valves E, a pair of micro-switch operated valves MV1, MV2, and one set of driving cylinders G, and a clutch cylinder I. The power generated by the power source A will be transmitted by a transmission element to the common valve G. Because the common valve C is first driven to open by the control device B, the power then passes through the common valve C into the clutch operating cylinder I to disengage the clutch. The clutch fork then presses the mechanical valve D and open it. The power is then transmitted to the control valve E. The output of gear box H can transmit the speed of the wheel to the control device B.The control device B will drive a valve of the control valve E open, then, the power will pass the valve and to the cylinder G. The cylinder G then drives the gear change lever right or left, forwards or backwards. The gear shifting lever will be set into the correct position, which is equivalent to the required speed ratio of the car. After that. because of the effect by the micro switch M beside the gear shift lever, the cylinder G then loses power, the mechanical element on the clutch, such as a spring, operates to engage the clutch. The operation of the gear change is then complete.

The power source may be compressed air, vacuum, or oil, and the control device can be an electrical or electronic control device or centrifugal control device. Therefore, there are many possible practical examples of the inventiion. I prefer the following example: With reference to Fig. 2 and Fig. 3, the preferred apparatus of this invention uses an electrical or electronic control device, and by means of compressed air as the power to pass through the electro-magnetic valve to the drive cylinder, then the clutch and gear change lever can be moved automatically or manually.

As shown in Fig. 2, the mechanical system comprises an air compressor 101, which can produce compressed air. The air compressor is driven by motor M or linking to the engine En by an electromagnetic linkage and belt. Thus, the air compressor will be driven to operate, and the produced compressed air will be stored in an air tank 102. By the side of the tank 102, there are a pressure switch, a safety valve and a pressure adjuster 103, which will keep the pressure of the compressed air in the tank constant.

The control device ("brain") includes a magnetic induction disc 12, a rotating needle 14 and contact points 15, 16, 17, 18. Electric conductor wires lead out from the contact points and are connected to relays 1 R. 2R.

3R. 4R. of each speed ratio respectively. The shaft of the rotating needle 1 4 is a flexible shaft. which is connected to the shaft of the speed meter of the car. Therefore, the rotating needle 1 4 can rotate and contact one of the contact points 15, 16, 17, 18 equivalent to the speed ratio of the car.

When the gear change lever is in the position of intermediate speed ratio, and the speed of the car continues to increase, then, with reference to Fig. 3, the contact needle of an induction disc of the control device rotates to point 17, the current will flow to a relay, and then, the common valve CV, the forward valve FV and rightward valve RV all close.

After that, referring to Fig. 2, the compressed air will pass through the common valve CV, pipe 114, check valve 111, and pipe 116, at last, flow to air cylinder C3, the air cylinder C3 then pulls the clutch 109 from the power shaft, and meantime, the micro switch valve MV2 becomes opened. The forward electromagnetic valve FC acts to close the rightward valves RV and the compressed air flows across valves MV2, FV, RV and pipes 118, 120. Then, the air cylinder C1 and C2 on the gear change lever acts to pull the gear change lever rightward and forward into the position of third gear, which is equivalent to the speed required ratio of the car.After the gear change lever has moved into the position equivalent to the required speed ratio of the car, with reference to Fig. 3, the contact points 2.4 of the limited switch LS open, and the contact points 2.3 of the limit switch LS close, thereby causing the limit switch LS to open. Simultaneously, the electromagnetic valves CV, FV, RV all open and the compressed air flows out. The cylinder C3 then loses the compressed air and the clutch 109 is pulled back to connect with the power shaft. Thus, the power from the engine transmits through the high speed gear of the gear box. The gear change is then complete.

If the clutch is disengaged, the engine En is unloaded. To avoid the no load speed increasing beyond a limit, another pipe 11 5 links the air cylinder C4. If the air cylinder C4 is driven by compressed air, the throttle control valve 105 in the carburetter will close partly, thereby avoiding the overspeed and decrease the fuel consumption.

In Fig. 2, the start solenoid SS, the check valve 111, the throttle valve 110, the micro switches MV1, MV2, and the throttle control valve 105 are all the important elements in making the clutch open or close.

The Valves MV1, MV2 CV, FV, BV, RV. LV are the electrically operated fluid pressure valves, wherein valves CV, FV, BV, RV, LV are solenoid valves, and valves MV1 MV2 are mechanical valves. The valves CV, FV, BV, RB, LV can be driven on by the electric current, and the valves MV1 MV2 can be driven on by mechanical force. Both of the valves of these two kinds are of well known type.

Other throttle valves may be provided in the lines 115, 118, 1 20 as shown.

Again with reference to Fig. 2, if the car is in driving condition and it is desired to stop it, the driver has to press down the brake pedal 1 22 by his foot. Thus, the speed of the car will decrease, the gear change lever than shifts into the position of low speed. Refer to Fig. 3, the limit switch Br on the brake pedal closes and makes the electric current flow through. At the same time, the electric current flows through the low speed contact point 15 of the control device, the relay BrB acts, points 5 and 7 contact and the electric current flows through, so as to make the common solenoid vave CV act and open. With reference to Fig. 12, after the valve CV opens, the compressed air from pipe 11 3 flows through CV, pipe 114, check valve 111, pipe 116, and then flows into air cylinder C3, the air cylinder C3 then opens clutch 109.Thus, after the car stops, the engine will continue to operate. At the same time, the compressed air in the pipe 11 5 will make the air cylinder C4 act, which will drive the throttle control valve 105 partly to close, and the engine then rotates at low speed.

If it is desired to start the car which is stopped, then the driver lifts the brake pedal and the car will begin to move slowly. After the brake is released, the limit switch Br as shown in Fig. 3 opens. Therefore, the contact points 5 and 7 of relay BrB open, and the common valve CV open, the electric current flows through the start solenoid SS, and opens the throttle air valve 104, to increase the power of the engine and the car will not stall. With reference to Fig. 2, after the valve CV is opened, the air then flows out of the pipe. The compressed air in the air cylinder C4 flows out from throttle control valve 105, and by the spring inside the air cylinder C4, the throttle control valve 105 will return to its original condition. The compressed air in the air cylinder C3 will flow from the mechanical valve MV1.But if the clutch is closed, the mechanical valve MV1 will then be closed.

Therefore. the compressed air in the air cylinder C3 will not be able to exhaust from the mechanical valve MV1, and check valve 111, and only can exhaust slowly from throttle valve 11 0. The operation of the clutch as mentioned above, will make the clutch engage quickly and then slowly. Thus, when the clutch engages, it will not cause shock.

For reversing, the automatic and hand operated switch 8 must still keep on position A, then the driver has to press down the brake pedal to make the car stop. After the car stops completely, he pulls the gear change lever to the reverse position, then releases the foot on the brake pedal, then the car will move in reverse. If the automatic system is out of order, operate the switch to position "B", then the car will be driven by hand.

The position C of the electric switch is used as the car is driven on a steep inclined plane.

Fig. 4 and Fig. 5 show a practical example of the structure between the gear change lever and the driving cylinders C, and C2. In this two Figure, it can clearly be seen that one of the cylinders C, will drive the gear change lever 1 forward and backward, the other cylinder C2 then drives the gear shifting lever rightward and leftward.

Claims (7)

1. A power transmission apparatus comprising a gear change member (1), gearchange means (C1) for driving the gear change member (1) forwards and backwards, gear change means (C2) for driving the gear change member (1) to the right and left, a clutch including a clutch engaging and disengaging member (109, 112), automatic clutch member operating means (C3), an automatic gear change control device (B), a main fluid pressure valve (CV) controlled by said control device (B), four fluid pressure electrically controlled gear change valves (FV, BV RV, LV) for actuating said gear change means (C1, C2) and controlled by said control device (B), a pair of micro switch operated valves (MV1, MV2) controlling said gear change valves and operated by the clutch engaging and disengaging member (109, 112); said main valve (CV) also being controlled by said microswitch valves, to provide fluid pressure from the main vlave (CV) through the micro switch valves (NV 1, MV2) to the gear change valves (FV, BV, RV, LV); said main valve also passing fluid pressure to said gear change means.

2. A power transmission apparatus as claimed in claim 1 wherein the control device includes a flexible shaft and a movable electric contact member connected with the flexible shaft said contact member serving to send signals to said valves.

3. A power transmission apparatus according to claim 1, wherein the control device (B) is an electric control type, and the rotating part of the control device is of the type of magnetic induction, which comprises a rotating needle, the rotating needle rotating according to the speed of the car, and making contact with contact points equivalent to the speed required ratio of the car.

4. A power transmission apparatus according to claim 1, wherein the automatic gear change means includes an operating cylinder, whereby the clutch member is engaged and disengaged and associated with the cylinder there are a check valve, a throttle valve and a mechanical valve which serve when the clutch engaged to avoid shock.

5. A power transmission apparatus according to claim 1, wherein in the carburetter, there is a throttle control valve, and a pipe is linked to an air cylinder, so that when the air cylinder receives compressed air, the throttle control valve in the carburetter will close partly, thereby avoiding overspeed and decrease the fuel consumption.

6. A power transmission apparatus according to claim 1, having a start solenoid on a throttle valve which makes the throttle valve open to avoid stalling the engine.

7. A power transmission apparatus substantially as described with reference to the accompanying drawings.