JPS61193933A - Vehicle with automatic clutch - Google Patents

Abstract

PURPOSE:To improve the operating performance for driving by automatically varying the contact speed of a clutch, in response to the intention of a driver. CONSTITUTION:The rotation of an engine 10 is transmitted to the right and left driving wheels through a clutch 12 and a speed change gear 14. The rotation number of the engine 10 is controlled by the control of throttle opening degree due to a stepping motor 17, and the stepping motor 17 is driven and controlled by an electronic controller 80. The clutch 12 is coupled to the output shaft of the engine 10 and the input shaft 22 of the speed change gear 14, and the clutch is connected and disconnected by actuation of an actuator 32, and the target value of actuating speed of the actuator 32 is determined by the rotation number of the engine and the more the rotation number of the engine increases, the more the time to connect the clutch decreases.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a vehicle equipped with an automatic clutch in a power transmission device that transmits the output of an engine to drive wheels.

In some prior art vehicles, a clutch provided in a power transmission device that transmits engine output to drive wheels is automatically engaged/disconnected by a clutch engagement/disconnection actuator. For example, vehicles with automatic transmissions are equipped with automatic clutches.

By the way, in this type of vehicle equipped with an automatic clutch, if the engagement speed of the latch at the time of starting, that is, the operating speed of the clutch engagement/disconnection actuator that engages the clutch is too high in relation to the engine speed, the ride comfort may deteriorate. , if it is too small, the time lag until the clutch engagement operation is completed becomes unnecessarily long, resulting in a decrease in driving operability. Therefore, conventionally, a constant engagement speed that is generally considered suitable for the entire range of engine rotational speeds when the clutch is engaged is selected, and the clutch engagement/disengagement actuator is operated at that engagement speed.

Problems to be Solved by the Invention However, in the above-mentioned conventional automatic clutch equipped vehicle in which the clutch engagement/disengagement actuator is always operated at a constant engagement speed when the clutch is engaged, the road surface is sloped upward when starting. Even if the driver presses down on the accelerator pedal and increases the engine speed because he or she wishes to start the vehicle particularly quickly, it takes an approximately constant amount of time for the clutch to engage. The vehicle did not start as intended by the driver, and its operability was not satisfactory. Furthermore, when the engine speed is low, such as when the vehicle starts idling, the contact speed of the clutch is too high, which causes the vehicle to not start smoothly, resulting in poor ride comfort.

Means for Solving the Problems The present invention has been made in order to solve the problem of the deterioration of riding comfort and driving operability due to the inappropriateness of the latching operation as described above. This is because, in a vehicle with an automatic clutch as described above, (a) a detection device that detects engine rotation speed or throttle opening; The present invention is provided with a clutch connection/disconnection actuator control device which makes the clutch connection speed of the Crabchi connection/disconnection actuator slow, and increases the speed when the clutch is opened at high speed or at a high opening.

Function and Effect In this manner, the clutch engagement speed is automatically changed in accordance with the driver's intention, which is expressed in the form of increasing the throttle opening by depressing the accelerator pedal and increasing the engine speed. In other words, if the driver wishes to start the vehicle quickly, the clutch is engaged in a short period of time to satisfy that wish, and in order to start the vehicle on an uphill slope, the driver presses the accelerator pedal. If the pedal is depressed deeply, the clutch is quickly engaged and the vehicle is effectively prevented from moving backwards. Additionally, if the driver wants to start the vehicle as slowly as possible and does not press the accelerator pedal or presses the accelerator pedal only slightly, the clutch is also engaged at a low speed and the vehicle starts smoothly. That will happen.

After all, according to the present invention, the operability of a vehicle equipped with an automatic clutch is improved and the ride comfort is also improved.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing a power transmission device for a forklift truck that is an embodiment of the present invention. As is clear from this diagram, in this embodiment, the rotation of the engine 10 is controlled by the clutch 12 and the transmission 14. The signal is transmitted to the left and right drive wheels 16 via the. The rotation speed of the engine 10 is controlled by controlling the throttle opening degree by a stepping motor 17, and the stepping motor 17 is driven and controlled by an electronic control unit (hereinafter simply referred to as ECU) 80, which will be described later. It has become.

The clutch 12 includes a flywheel 20 fixed to the output shaft 18 of the engine 10, a clutch disc 24 mounted non-rotatably but movably in the axial direction to the input shaft 22 of the transmission 14, and the clutch disc 24. It is equipped with a pressure plate 26 that faces the flywheel 20 and is provided so as to be immovable relative to the flywheel 20 and movable in the axial direction. 2
4 is sandwiched between the flywheel 20 and the pressure plate 26, thereby connecting the output shaft 18 of the engine 10 and the input shaft 22 of the transmission 14.
0 rotation of the output shaft 18 is transmitted to the input shaft 22 of the transmission 14. On the other hand, pressure plate 2
6 is connected to an actuating arm 30 that is driven by the actuation of a clutch engaging/disengaging actuator 32. When the actuating arm 30 is driven by the actuator 32, the pressure plate 26 resists the biasing force of the clutch spring 28. It can be moved in a direction away from the flywheel 20. As a result, the clutch disc 24 is released from being held between the flywheel 20 and the pressure plate 26, and the output shaft 18 of the engine 10 and the input shaft 24 of the transmission 14 are
The rotation of the output shaft 18 of the engine 10 is no longer transmitted to the input shaft 22 of the transmission 14.

The transmission 14 also includes a gear ratio switching gear section 36 for switching between 1st and 2nd speeds and a forward/reverse switching gear section 38. The signal is transmitted to the output shaft 40 via the forward/reverse switching gear section 36 and the forward/reverse switching gear section 36, and from the output shaft 40 to the left and right drive wheels 16 via a differential gear device (not shown). A first-speed manual gear 42 and a second-speed manual gear 44 are fixed to the input shaft 22, and each is connected to a first-speed reduction gear 46.
and is meshed with the second speed reduction gear 48. Further, a connecting gear 50 is fixed to each of these reduction gears,
These connecting gears 50 are arranged coaxially with and sandwiching an output gear 54 fixed to a connecting shaft 52 that connects both gear parts 36 and 38. A shift increment gear 56 is provided on the outer periphery of these gears, and a shift actuator 58 connects the output gear 54 to the first speed side connection gear 50 at the first speed shift position and the second speed side connection. It can be moved between three positions: a second speed shift position, which is connected to the gear 50, and an intermediate neutral shift position, which is not connected to the connected gear 50. Shift actuator 5
When the increment null gear 56 is moved to the neutral position by 8, rotation is not transmitted to the connecting shaft 52, but when the increment null gear 56 is moved to the first gear shift position, the rotation of the input shaft 22 is transmitted to the input for the first gear. Gear 42. The rotation of the input shaft 22 is transmitted to the connecting shaft 52 via the reduction gear 46 and the connecting gear 50, and when the gear is moved to the second gear shift position, the rotation of the input shaft 22 is transmitted to the second gear input gear 44°, the reduction gear 48, and the connecting gear 50. The signal is transmitted to the connecting shaft 52 through the .

On the other hand, a forward/reverse input gear 60 is fixed to the connecting shaft 52, and is disposed coaxially with the forward connecting gear 62 and the reverse connecting gear 64 while being sandwiched between them. The outer periphery of these gears has a forward movement position where the input gear 60 is connected to the forward movement connection gear 62 by the forward/reverse movement switching actuator 66, a reverse movement position where the input gear 60 is connected to the reverse movement connection gear 64, and a position where the input gear 60 is connected to the forward movement connection gear 64. An increment null gear 68 for forward/reverse switching is provided which can be moved between three positions including a neutral forward/reverse position which is an intermediate position where the two are not coupled. The rotation transmitted to the forward coupling gear 62 is transmitted from the forward input gear 70 to the output shaft 40 via the forward output gear 72, and the rotation transmitted to the reverse coupling gear 64 is transmitted to the reverse input gear 72. The signal is transmitted to the output shaft 40 via the 742 reversing gear 76 and the reverse output gear 78, and is transmitted to the drive wheels 16 via the output shaft 40, respectively.

In this way, the engagement and disengagement of the clutch 12, the switching of the gear ratio in the transmission 14, and the switching between forward and backward travel are performed by the clutch engagement and disconnection actuator 32, the shift actuator 58, and the forward/reverse switching actuator 66, respectively. However, in this embodiment, all of these actuators are hydraulic cylinders, and the above-mentioned E
It is driven by a hydraulic circuit controlled by CU3O. Figure 2 shows the hydraulic circuit. The hydraulic circuit shown in Fig. 2 will be explained below, but for ease of understanding, the chamber on the cylinder head side of each actuator (hydraulic cylinder) will be referred to as the head side chamber, and the chamber on the piston rond side will be referred to as the rod side chamber. do.

In FIG. 2, the hydraulic oil pumped up from the tank 82 by the pump 84 is stored in the accumulator 86 and then supplied to the main liquid passage 87, from which the control valve mechanism of the clutch engagement/disconnection actuator 32 is supplied. directly to the clutch control valve mechanism 88, which is the shift actuator 58, and to the shift control valve mechanism 90 and the forward/reverse switching control valve mechanism 92, which are the control valve mechanisms of the shift actuator 58 and the forward/reverse switching actuator 66, via the main electromagnetic on-off valve 94. It is now being supplied. The main electromagnetic on-off valve 94 is always closed, so the main fluid is connected to the shift control valve mechanism 90 and the forward/reverse switching control valve mechanism 92 only while the main electromagnetic on-off valve 94 (more precisely, its solenoid) is energized. aisle 87
Hydraulic oil is supplied from.

The clutch control valve mechanism 88 includes a first human-powered electromagnetic on-off valve 96 that can rapidly supply hydraulic oil from the main fluid passage 87 to the head side chamber 95 of the clutch connection/disconnection actuator 32, and a throttle. a second human-powered electromagnetic on-off valve 98 that can gradually supply hydraulic oil to the head side chamber 95;
A first output electromagnetic on-off valve 102 that can rapidly discharge the hydraulic oil in the head side chamber 95 to the tank 82 via the drain passage 100.
and a second output electromagnetic on-off valve 104 which is equipped with a throttle and is configured to gradually discharge the hydraulic oil in the head side chamber 95 into the tank 82 through the drain passage 100. By controlling this, hydraulic oil can be supplied and discharged to and from the head side chamber 95 of the clutch engagement/disconnection actuator 32 at a desired speed.

In the clutch connection/disconnection actuator 32, the piston rod 106 is moved by air against the urging force of the clutch spring 28 which is applied via the actuation arm 30 according to the amount of hydraulic oil in the head side chamber 95. The pressure plate 26 is moved forward (extended) toward the rod side chamber 107, which is a chamber, and the pressure plate 26 is moved in a direction away from the flywheel 20 via the actuating arm 30, as described above. In this clutch control valve mechanism 88, only the second output electromagnetic on-off valve 104 is always opened, so the piston rod 106 is always opened in the head side chamber 9 based on the biasing force of the clutch spring 28.
It is retracted or contracted to the 5 side.

The shift control valve mechanism 90 consists of two electromagnetic on-off valves 108 and 110 connected in series between the main electromagnetic on-off valve 94 and the drain passage 100. It is connected to a connecting passage 114 connecting the on-off valves, and a rod side chamber 116 is provided in a state connected to the main electromagnetic on-off valve 94. In a normal state where both electromagnetic on-off valves 108 and 110 are open, the head side chamber 11 of the shift actuator 58
The piston is moved between the head side chamber 112 and the rod side chamber 11 without applying hydraulic pressure to both the head side chamber 112 and the rod side chamber 116.
6, and the shift ink null gear 56 is held at the neutral shift position. However, with the main electromagnetic on-off valve 94 open, the electromagnetic on-off valve 108 is held in the neutral shift position.
When closed, hydraulic oil is supplied only to the rod side chamber 116 side, the piston rod 118 is contracted, and the internal gear 56 is moved to the first gear shift position. When the electromagnetic on-off valve 110 is closed while the main electromagnetic on-off valve 94 is open, hydraulic pressure is applied to both the head side chamber 112 and the rod side chamber 116, and the difference in pressure receiving area between the two chambers is applied. Extend the piston rod 118 and connect the ink null gear 5.
6 to the second gear shift position.

Further, as is clear from FIG. 2, the forward/reverse switching control valve mechanism 92 also consists of two electromagnetic on/off valves 120 and 122 connected in series between the main electromagnetic on/off valve 94 and the drain passage 100. , the head side chamber 124 of the forward/reverse switching actuator 66 connects the two electromagnetic on-off valves with a connecting passage 126.
The rod side chamber 128 is connected to the main electromagnetic on-off valve 94. Both electromagnetic on-off valves 120 and 122 are normally opened to maintain the piston rod 130 at an intermediate position and to maintain the forward/reverse switching inclination gear 68 of the transmission 14 at a neutral forward/reverse position. When the solenoid on-off valve 120 is closed while the main solenoid on-off valve 94 is open, the piston rod 130 is contracted to move the internal gear 68 to the forward position, and when the main solenoid on-off valve 94 is open, the piston rod 130 is contracted and the internal gear 68 is moved to the forward position. When the electromagnetic on-off valve 122 is closed, the piston rod 130 is extended and the internal gear 68 is moved to the reverse position.

As shown in FIG. 3, the ECU 3O that drives and controls the stepping motor 17 and each electromagnetic on-off valve of the hydraulic circuit is mainly composed of a CPU 134 equipped with a memory 132, and receives input from various sensors. The CPU 134 processes the information signal according to a program stored in advance in the memory 132, and drives each electromagnetic on-off valve and the stepping motor 17 of the hydraulic circuit based on the result of the calculation process. That is, analog signals such as the accelerator depression amount, the clutch stroke, and the engine coolant temperature are digitized and input to the CPU 134 from each sensor via the input interface circuit 138 and the A/D converter 140. , a forward command, a neutral command, a reverse command, and an accelerator idle state via the input interface circuit 142.

Inching eyed raw state. 1st speed shift position state, neutral shift position state, 2nd speed shift position state, forward position state.

Neutral forward/backward position, reverse position, maximum throttle position, minimum throttle position, engine rotation, and vehicle speed.

Various on/off signals such as brake operation status and loading oil pressure are inputted, and solenoid drive signals for the electromagnetic on-off valves and stepping motor 17 are also input from the CPU 134 via an output interface circuit 144.
The drive signal is outputted.

Incidentally, the amount of accelerator depression is determined by the accelerator sensor 14 provided on the accelerator 146, as shown in FIG.
8, and the rotation of the engine 10 is detected by a magnetic gear 150 fixed to its output shaft 18 and a magnetic sensor 1.
52, and the vehicle speed is detected by a vehicle speed sensor 160, which includes a magnetic gear 156 and a magnetic sensor 158, which are fixed to the output shaft 40 of the transmission 14. Further, the clutch stroke is detected by a potentimeter 162 attached to the clutch engagement/disconnection actuator 32, and each shift position state and each forward/reverse position state is detected by the shift actuator 58 and the forward/reverse switching actuator 66, respectively.
It is detected by the operating state of a switch (not shown) provided in the. Note that other information signals are also detected by sensors or switches provided correspondingly to each, but all of these are
Since this is well known, its explanation will be omitted.

The memory 132 of the CPU 134 stores various control programs including the program shown in the flowchart shown in FIG. The operation of the apparatus of this embodiment will be explained below according to the flowchart shown in FIG.

When the program starts, step Sl is first executed, and it is determined whether the direction switch that determines the direction of travel of the vehicle has been switched to a state that issues a forward command or a reverse command.

If the result of the determination is No, step s1 is repeated, and if YES, step s2 is executed.

In step S2, the engine rotation speed at that time is determined based on the rotation signal from the engine rotation sensor 154. Then, in the following step S3, step S
The target value of the engagement speed of the clutch 12, that is, the clutch engagement/disconnection actuator 32 is determined from the engine rotation speed determined in step 2.
The target value of the operating speed is determined. As shown in FIG. 5, the clutch engagement/disengagement actuator 32 is operated at a constant high speed until the clutch 12 is in the half-engaged state, and in the constant stroke region where the clutch 12 is in the half-engaged state, the clutch is engaged/disconnected. If the operating speed of the actuator is V and the engine speed is n, it can be operated at a speed determined by v=an+b,
This calculation is performed. Furthermore, a.

b is a constant, in particular a is a positive constant. That is,
When the engine speed is high, the operating speed of the clutch engagement/disconnection actuator is also determined to be high.

Step S4 executed following step S3 above
In this step, the actuator 32 is operated at a speed that corresponds to its target value. Both input electromagnetic on-off valves 96 and 98 of the clutch control valve mechanism 88 are closed, and the opening and closing of both output electromagnetic on-off valves 102 and 104 are duty-controlled, and hydraulic oil is discharged from the head side chamber 95 of the actuator 32. The speed is controlled so that the operating speed of the actuator 32 is controlled to match the target value.

Step S5 is executed following step S4, and it is determined based on the clutch stroke signal from potentiometer 162 whether the engagement operation of clutch 12 is completed. As long as the result of this determination is negative, step S4 is continued, but if the result is affirmative, the execution of this program ends.

As described above, in this embodiment, the target value of the operating speed of the clutch engagement/disconnection actuator 32 when the vehicle starts is determined according to the engine speed at that time, and the clutch engagement/disconnection actuator 32 is determined in this way. The higher the engine speed, the more quickly the clutch 12 is engaged (in other words, in a short time after the direction switch is switched to the state where the forward command or reverse command is issued). By depressing the accelerator pedal and increasing the engine speed, the driver can quickly start the vehicle on flat ground, and prevent the vehicle from going backwards on an uphill road. It can be prevented. Further, in an idling state or a near-idle state in which the accelerator pedal is not depressed, the clutch is gently brought into contact by a connecting/disengaging actuator that operates at low speed, and the vehicle is slowly started.

As is clear from the above description, in this embodiment, the engine rotation sensor 154 and the CP that executes step S2
A detection device is constituted by U134, and step S
A control device is composed of a CPU 134 that executes steps 3 to S5 and a clutch control valve mechanism 88.

Although one embodiment of the present invention has been described above, this is literally an illustration, and the present invention should not be interpreted as being limited to the above embodiment.

For example, in the above embodiment, the operating speed of the clutch engagement/disconnection actuator is calculated to be proportional to the engine speed, but the target value of the operating speed is determined for each range of engine speed. It is also possible to determine the target value of the actuation speed by creating a table in advance and storing it in the memory of the control device.

It is also possible to detect the throttle opening instead of the engine speed and determine the target value so that if the throttle opening is large, the clutch contact speed will be high, and if it is small, the clutch contact speed will be small. It is. In this case, the throttle opening degree can be determined not only by directly detecting the opening degree of the throttle valve itself, but also by detecting the throttle opening degree based on the amount of depression of the accelerator pedal.

Further, in the above embodiment, the power transmission device was equipped with only one clutch 12 common to both forward and reverse motions, but in the present invention, the transmission is a constant mesh planetary gear unit. In addition, it can also be applied to a vehicle equipped with a power transmission device having a plurality of clutches, such as a forward clutch and a reverse clutch.

Further, although the present invention is suitably applied to industrial vehicles such as the forklift truck of the above embodiment, it can also be applied to other vehicles such as passenger cars.

Although not listed here, it goes without saying that the present invention can be practiced with various modifications and improvements without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing a power transmission device for a forklift truck, which is an embodiment of the present invention. FIG. 2 is a circuit diagram showing an example of a hydraulic circuit for operating each actuator shown in FIG. 1. FIG. 3 is a block diagram showing details of the electronic control system of FIG. 1. FIG. 4 is a flowchart for explaining the operation of the power transmission device of FIG. 1. FIG. 5 is a graph showing the relationship between the operating stroke of the clutch engagement/disconnection actuator in the power transmission device of FIG. 1 and time. 10: Engine 12: Clutch 14: Transmission 32: Clutch connection/disconnection actuator 58: Shift actuator 66: Forward/forward switching actuator 80: Electronic control device 88: Clutch control valve mechanism 90: Shift control valve mechanism 92: Forward/forward switching Control valve mechanism 148: Accelerator sensor 154: Engine rotation sensor 160: Vehicle speed sensor 160: Potentiometer

Claims (1)

[Scope of Claims] A vehicle with an automatic clutch in which a clutch provided in a power transmission device that transmits engine output to drive wheels is automatically engaged/disconnected by a clutch engagement/disconnection actuator, wherein: a detection device that detects a throttle opening; and when the detection result of the detection device is a low speed or a low opening, the speed of the clutch connecting actuator of the clutch connection/disconnection actuator is set to a low speed; 1. A vehicle with an automatic clutch, characterized in that it is provided with an actuator control device for clutch engagement/disconnection, which can be performed at high speed in some cases.