JPH0242696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a stepless transmission system for a vehicle having an internal combustion engine, in which the transmission ratio of the transmission system is controlled as a function of input parameters related to load and rotational speed. The present invention relates to an apparatus of the type having a first positioning part and a second positioning part for determining the transmission ratio.

Prior Art In known control devices of this type,
A rod is connected to the accelerator pedal. When the accelerator pedal is moved, the rod rotates a cam disk which acts on an actuating member of a hydraulically and/or pneumatically controlled transmission. The transmission is configured as a V-belt transmission with two pulleys, the effective diameter of which is variable. Continuous transmissions of this type are therefore used in particular to operate internal combustion engines as constantly as possible so that optimum fuel consumption occurs. For this purpose, the control device of the transmission is constructed as follows. In other words, the aim is to obtain as much as possible a transmission ratio that allows the internal combustion engine to always rotate at the optimum rotational speed for the particular driving condition, thus resulting in the lowest fuel consumption, and to generate the torque, no matter what driving condition the vehicle is in. It is configured so that it can be used.

Problems to be Solved by the Invention However, in the above-mentioned known control device,
It is difficult to adapt to different types of internal combustion engines, each of which has a different characteristic curve for optimum torque. Furthermore, because the accelerator pedal position is mechanically transmitted, defects due to mechanical inaccuracies of the rod remain unavoidable.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to eliminate the above-mentioned drawbacks.

Means for Solving the Problems According to the present invention that solves the above problems, the first positioning portion is actuated in accordance with the static pressure of the fluid.
a second actuating member for actuating the second positioning portion in response to the static pressure of the fluid; a pressure supply device for providing the static pressure of the fluid; an electronic controller comprising a computer for transmitting an electrical output signal, and the first actuating member controls the static pressure supplied from the pressure supply device to the connecting portion of the first positioning portion to the first positioning portion. at least one valve controlled in response to an electrical output signal of a second actuating member, the second actuating member is adapted to direct the static pressure supplied from the pressure supply device to the connection of the second positioning part to a second actuating member; The valve comprises at least one valve that is controlled in response to an electrical output signal of the electronic controller, and the valve that constitutes the first actuating member and the valve that constitutes the second actuating member are the first and second valves of the electronic controller. They can be controlled independently and selectively by the electrical output signals of the two.

Effects According to the invention, the signals used for the direct control of the transmission can be easily and accurately detected in accordance with the characteristic curve of each engine, without additional defects, and can be electrically or The advantage is that the actuating member of the transmission is fed by means of fluid, ie hydraulic or pneumatic forces. In this case, the same electronic controller can be used for vehicles with different types of drive engines, especially road vehicles. The electronic controller is preferably a microcomputer,
In particular, it has a microprocessor. The consideration of different characteristic curves is made in a simple manner by incorporating the memory element into the computer. In this case, the characteristic curves of the engine and, if necessary, other data are also stored in the memory element.

Advantageous embodiments of the invention are described in the subclaims 2 and 4 to 7. According to the embodiment according to paragraph 2, the pump is able to convey pressure medium directly to the return path with only a small power loss once the pressure accumulator is filled. When the pressure energy regulating the continuously variable transmission is removed from the pressure accumulator, that is to say when the pressure in the pressure accumulator drops, the unloading valve is switched over again to convey pressure medium to the pressure accumulator. The unload valve is configured such that the unload valve has hysteresis between an opening pressure and a closing pressure. According to the embodiment described in claim 3, control can be performed without using a mechanical detection means inside the control device of the transmission device. In an advantageous embodiment, the electrical signals sent by the electronic control can act directly on the actuating elements of the transmission. In many cases, it is structurally simple to first convert the electrical signals of the electronic control into pressure signals, in particular hydraulic pressure signals. The embodiment described in claim 4 includes:
A valve or valves are provided that provide variable pressure to the actuating member.

Embodiment Next, the structure of the present invention will be specifically explained based on the illustrated embodiment.

The V-belt transmission device 1 shown in FIG. to be done, second
It has a pulley 4. second pulley 4
are connected to the drive wheels of the motor vehicle in a manner not shown. The two pulleys 2, 4 each have two parts, a positioning part 8 or 8' and a further part 7 or 7', which are guided so as to be axially movable relative to each other. . these two parts 7, 8 or 7',
8' are non-rotatably connected to each other. By introducing a pressure medium, in this example oil, into the chamber 9 or 9', the movable positioning part 8,
8' in the direction of the other part 7, 7', and
Positioning part 8, 8' where the belt 3 is located
It is possible to reduce the annular distance between the two parts 7, 7' and the other part 7, 7'. By reducing the annulus, the V-belt is forced radially outward and the effective diameter of the pulley increases. When the pressure in chamber 9 or 9' decreases, V
The belt 3 causes the positioning part 8 or 8' to separate from the other part 7, 7' again, as long as a sufficient tightening force is applied to the V-belt 3. The oil is
Filter 1 is removed from oil tank 12 by pump 11.
3 and from the pressure side of the pump 11 reaches the connection 15 of the second pulley 4 on the one hand and the connection 25 of the first pulley 2 on the other hand via the valves described below. . This pump 11 and pressure accumulator 47 form a pressure supply device.

The pressure side of the pump 11 is connected to the inlet of the unload valve 45 . The slider of the unloading valve 45 is loaded against the force of the spring 46 by the pressure prevailing at the outlet of the unloading valve 45 . When this pressure reaches a predetermined value, the unload valve 45 sends the oil supplied by the pump 11 directly to the return path without load, ie with very little power loss of the pump. A pressure accumulator 47 is connected to the outlet of the unload valve 45, and in addition, a 3-port 3-position directional switching valve 49 as a first actuating member and a 3-port 3-position directional switching valve 49 as a second actuating member are connected. A position direction switching valve 48 is connected. These directional valves 48, 49 each have three switching positions and three connections and, depending on the switching position, can either increase the pressure in the associated pulley or keep it constant. (switching position shown in Figure 1) or lowered. If the pressure in the associated pulley is to be increased, each connection 25, 15 is connected to the outlet of the associated valve and thus to the pressure accumulator 47. To reduce the pressure, each connection 25, 15 is connected to a return path and thus to the oil tank 12.
connected to. The inlets of the two directional valves 48 , 49 (second and first actuating member) are connected to each other and to the pressure accumulator 47 by a conduit 50 . The return path is connected via a conduit 51 to a connection leading to the oil tank 12 . The directional control valves 48 and 49 are controlled by electrical signals sent by an electronic controller 55. This electronic controller 55
are connected via separate output circuits 56, 57 to the electrical control inputs of directional valves 48, 49, which are constructed as solenoid valves. Electronic controller 55
is supplied with a rotational speed signal for the second pulley 4, which is sent out by a rotational speed signal generator 44. In addition, this electronic controller 55 can, in the illustrated form, receive input signals for the position of a selection lever (not shown) for power transmission, as well as for the position of a regulating valve or in a suitable other form, e.g. A load signal and a rotational speed signal of the internal combustion engine are supplied by means of the underpressure generated in the intake duct of the engine. In addition, electronic controller 55 is also supplied with signals originating from pressure transducer 43 for the pressure for the hydraulic line leading to connection 15 . These input signals cause the electronic controller 55 to determine the selected transmission ratio of the V-belt transmission 1 in connection with the respective driving state, taking into account the minimum fuel consumption characteristic curve of the internal combustion engine used. The second and first actuating members configured as electromagnetic directional control valves 48, 49 are controlled in accordance with the detected transmission ratio. By comparing the rotational speeds, it is possible to confirm how much the actual transmission ratio differs from the adjusted transmission ratio. Hydraulic conduits are shown in solid lines in FIG. 1, while electrical circuits are shown in dotted lines.

Electronic controller 55 according to the embodiment shown in FIG.
has a signal processing device 59, as can be seen from FIG. The signal processing device 59 receives the driven side rotational speed signal of the second pulley 4, the engine rotational speed signal, and the load signal and position signal of the selection lever of the transmission device (for example, reverse driving, no-load driving, low-speed driving). , high speed travel, etc.) are sent, and the signal processing device 59 puts these signals into the required form for further processing. These signals are further sent to a calculator, which in this embodiment is a microprocessor 60. Microprocessor 60 is connected to a power source and a pulse generator 61. The output signal of microprocessor 60 is sent to terminal stages 62, 63 from where it is amplified and reaches directional valves 48, 49.

As shown in FIG. 3, the microprocessor 60 having a transmission ratio calculator function calculates the actual state (the operating state of the internal combustion engine and the transmission) and calculates the internal combustion engine stored in the storage device 65. The optimum transmission ratio is detected by the consumption characteristic curve. The actual transmission ratio and the optimum transmission ratio are compared in a comparator 66. The output signal of comparison device 66 is sent to another comparison device 67. A limit value signal, which is not allowed to be exceeded, is sent to a further input of the comparison device 67. These limit values are detected by a unit 68 to which the maximum rotational speed and the minimum rotational speed are previously given as functions of the input quantities. These limit values also limit the adjustment of the transmission in relation to the positions of the selection switch and the kick-down switch. The output signal of the comparator 67 corresponds to the target value of the transmission ratio. Based on this target value, the pressure calculator 6
9, a directional valve 4 configured as a solenoid valve
8 and 49 are detected. If the transmitted torque is high, the pressure in the pulleys 2, 4 is greater than if the transmitted torque is small.

In FIG. 1, some components are surrounded by dash-dotted lines. These components are
Other components can be substituted as in the embodiment shown in FIG. Instead of the three-port three-position directional valves 48, 49 used in the embodiment shown in FIG.
In the illustrated embodiment, the first actuating member is a 3-port 2
It is formed of a position direction switching valve 71 and a 2-port 2-position direction switching valve 73, and the second actuating member is
It is formed from a 3-port 2-position directional switching valve 70 and a 2-port 2-position directional switching valve 72. In the switching position shown, the pressure in the pulleys 2, 4 remains constant. This is because the two-port, two-position directional valves 72, 73 are closed.
When the 2-port 2-position directional control valves 72, 73 are located at different switching positions, the chambers 9, 9'
The pressure within increases or decreases. These directional control valves 70, 71, 72, and 73 are configured as electromagnetic valves, and are controlled by electrical signals transmitted by an electronic controller 55. The electronic controller 55 in this embodiment differs from the embodiment shown in FIG. 1 in the following points. That is, it is configured to be suitable for controlling four directional switching valves instead of two directional switching valves. The input signals to electronic controller 55, however, are the same as those used in the embodiment shown in FIG.

The invention is not limited only to V-belt transmissions, but is also applicable to other continuously variable transmissions, in particular continuously adjustable links provided with discs or wheels with a variable effective diameter. Can be applied to belt transmission devices.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, in which FIG. 1 is a schematic diagram of a V-belt transmission device having a control device according to the first embodiment, and FIG. 2 is a diagram showing an electronic control of the control device shown in FIG. 3 is a detailed configuration diagram of the controller shown in FIG. 2, and FIG. 4 is a schematic diagram showing a modification of the control device shown in FIG. 1. 1... V-belt transmission device, 2... Pulley, 3
... V-belt, 4... Pulley, 7, 7'... Other part, 8... First positioning part, 8'...
Second positioning portion, 9, 9'...chamber, 11...
pump, 12...oil tank, 13...filter,
15, 25...Connection part, 43...Pressure transducer, 4
4... Rotation speed signal generator, 45... Unload valve, 46... Spring, 47... Pressure accumulator, 48, 49
...3 port 3 position directional valve, 50, 51...
Conduit, 55... Electronic controller, 56, 57... Output circuit, 59... Signal processing device, 60... Microprocessor, 61... Pulse generator, 62, 63
...Terminal stage, 65...Storage device, 66, 67...
Comparison device, 68... Unit, 69... Pressure calculator, 70, 71... 3 port 2 position directional valve,
72, 73...2 port 2 position directional control valve.

Claims (1)

[Scope of Claims] 1. A control device for controlling a transmission ratio of a transmission device as a function of input parameters related to load and rotation speed in a continuously variable transmission device for a vehicle having an internal combustion engine, the control device determining the transmission ratio. a first actuating member 49 for actuating the first positioning part 8 in response to the static pressure of the fluid;
71, 73 and a second actuating member 48 for actuating the second positioning part 8' in response to the static pressure of the fluid;
0,72, a pressure supply device 11,47 for supplying static pressure of the fluid, and a calculator 6 for emitting first and second electrical output signals as a function of said parameters.
An electronic controller 55 consisting of 0 is provided,
The first actuating member is configured by at least one valve for controlling the static pressure supplied to the connection 25 of the first positioning part 8 by the pressure supply device 11, 47 in response to a first electrical output signal. The second
The actuating member comprises at least one valve for controlling the static pressure supplied by the pressure supply device 11, 47 to the connection 15 of the second positioning part 8' in response to a second electrical output signal. The valve constituting the first actuating member and the valve constituting the second actuating member can be controlled independently and selectively from each other by the first and second electric output signals of the electronic controller 55. A control device for a continuously variable transmission device, characterized in that: 2. The pressure supply device is composed of a pump 11 and a pressure accumulator 47, and the pressure accumulator 47 is filled with fluid under the pressure created by the pump 11. Control device. 3 An unloading valve 45 is connected downstream to the pump 11 for pressure medium, and this unloading valve 4
5 is a control device according to claim 2, which disconnects the pump 11 from the pressure accumulator 47 and connects it to the return path when the pressure accumulator 47 exceeds a predetermined pressure. 4. The control device according to claim 1, further comprising a pressure sensor 43 for emitting an electrical signal related to the pressure of the fluid, the pressure sensor being electrically connected to an electronic controller 55. 5 the first actuating member is for controlling static pressure;
The first 2-port 2-position directional control valve 73 and the first 3
It consists of a port 2 position directional control valve 71,
The inlet of the first 2-port 2-position directional control valve 73 is connected to the outlet of the first 3-port 2-position directional control valve 71, and the second actuating member is connected to the second 2-port 2-position directional control valve 71. It consists of a switching valve 72 and a second 3-port 2-position directional switching valve 70, and the inlet of the second 2-port 2-position directional switching valve 72 is connected to the second 3-port 2-position directional switching valve 72.
The control device according to claim 1, which is connected to the outlet of the port 2 position directional control valve 70. 6 The first actuating member is a first actuating member that controls the static pressure.
The second actuating member is configured as a port 3 position directional valve 49, and the second actuating member is configured as a port 3 position directional valve 49.
The port 3 position is configured as a directional switching valve 48, the inflow ports of these directional switching valves 48, 49 are commonly connected to the discharge port of the pump 11, and the return ports of these directional switching valves 48, 49 are common. The control device according to claim 1, wherein the control device is connected to the suction port of the pump 11. 7. The control device according to claim 1, further comprising an internal combustion engine characteristic curve storage device 65.