JPH11351277A - Vehicle power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the accompanying rotation of a clutch, and to detect the uncoupling of the clutch in an early stage. SOLUTION: A vehicle power transmission to transmit the power of an engine 76 to a transmission 75 through a wet-type multiple disk clutch is provided with a first detecting means 103 to detect the input side number of revolution of the clutch, a second detecting means 93 to detect the output side number of revolution of the clutch, a signal generating means 95 to generate the clutch uncoupling starting signal, and a control means 79 which starts the uncoupling of the clutch when the clutch uncoupling starting signal is received from the signal generating means 95, and keeps the engine speed until the difference in the number of revolution between the input and output sides of the clutch to be calculated based on the outputs of the first and second detecting means 103, 93 reaches a specified value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle power transmission device.

[0002]

2. Description of the Related Art A hydraulically controlled wet multi-plate clutch is known as a device for transmitting the power of an engine to a transmission. As shown in FIG. 5, this includes a plurality of clutch plates housed in a clutch housing 116, that is, a drive plate 114 and a driven plate 111.
Are pressed against each other by a clutch piston 120 to obtain a clutch fastening force. The hydraulic pressure controlled to an appropriate value as shown by an arrow is supplied to the clutch piston 120 through a hydraulic passage 119. On the other hand, when the hydraulic pressure is discharged, the clutch piston 120 is pushed back by the return spring 121, whereby the pressing force of the clutch plate is lost and the clutch is disconnected.

[0003] The clutch housing 116 forms the input side of the clutch, and its input shaft 118 is connected to the crankshaft (not shown) of the engine to obtain the power of the engine. On the other hand, an output shaft 113 is inserted into the clutch housing 116 so as to be relatively rotatable, and is connected to an input shaft (not shown) of the transmission so as to form an output side of the clutch. The drive plate 114 is attached to the clutch housing 116, and the driven plate 111 is attached to the output shaft 113 via the clutch holder 112. The attachment of each clutch plate is performed via splines.

FIG. 6 shows a hydraulic supply device. The oil pump 125 is driven by the engine to draw oil from the oil tank 126 and discharge it to the clutch piston 120 and the clutch lubrication system. During this process, the flow rate and pressure of the oil are controlled by the variable throttle valves 127 and 128. The supply / discharge of oil to / from the clutch piston 120 is switched by an electromagnetic switching valve 129. 130 is a relief valve.

[0005]

The clutch plate of the wet multi-plate clutch is included in the clutch lubrication system and is supplied with oil. This is because oil releases frictional heat generated when the clutch is engaged. Therefore, the clutch plate is slightly dragged by the oil viscosity.

On the other hand, when controlling the hydraulic pressure of the clutch, it is necessary to detect the connection / disconnection of the clutch. Generally, the hydraulic pressure between the clutch piston 120 and the electromagnetic switching valve 129 is detected by the hydraulic pressure sensor 131 as shown in FIG. Although not shown, a clutch input / output side rotational speed difference is detected by using an engine rotation sensor and an input shaft rotation sensor of a transmission to detect connection / disconnection of the clutch.

Here, the control response of the clutch is greatly affected by the oil temperature. For example, at the time of starting the engine (particularly at the time of starting at a low temperature), the oil has a low temperature and a high viscosity, so that the drag of the clutch plate increases and the pressure loss in the hydraulic circuit and the valve also increases, so that the control response deteriorates. That is, there is a problem that it is difficult to accurately detect the disconnection of the clutch particularly in the wet multi-plate clutch.

As a countermeasure against this, it is conceivable to detect the oil pressure in the vicinity of the clutch piston in the former method of detecting the oil pressure. However, as shown in FIG. Impossible. Therefore, the latter method of detecting the rotational speed difference is generally used in many cases.

However, this method also has the following problems. In other words, in this method, when the difference between the engine speed and the input shaft speed exceeds a certain value,
It is determined that the clutch is disengaged. However, due to the drag effect described above, the clutch plate may rotate even though there is no pressing force on the clutch plate, and the increase in the rotational speed difference may be delayed, and the detection of clutch disengagement may be delayed.

Accordingly, in order to compensate for this, the oil pressure detection is also used, and it is determined that the clutch is disconnected when a predetermined time has elapsed after the oil pressure has decreased, or until the rotational speed difference from the start of the clutch disconnection at high oil temperature reaches a certain value or more. Learn the time for each gear break,
Methods such as referencing this value at low oil temperature are adopted, but none of these are fundamental solutions.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a vehicle power transmission device for transmitting the power of an engine to a transmission via a wet-type multi-plate clutch, and detects an input-side rotational speed of the clutch. Detecting means for detecting the output-side rotational speed of the clutch.
Detecting means, a signal generating means for generating a clutch disconnection start signal, and upon receiving a clutch disconnection start signal from the signal generating means, starting the disconnection of the clutch, and the first and second detecting means And control means for maintaining the engine rotation until the clutch input / output-side rotation speed difference calculated based on the output of the clutch reaches a predetermined value.

According to this, the rotation of the engine is forcibly held, so that the co-rotation is prevented, whereby the clutch disconnection can be detected earlier.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a power transmission device according to the present invention. As shown, in such a device, a clutch torque converter unit 50 is provided between an engine 76 and a transmission (T / M) 75.
As will be described in detail later, the clutch torque converter unit 50 is a unit in which a hydraulically controlled wet multi-plate clutch and a torque converter are combined in series and housed in the same housing. The transmission 75 is a manual transmission itself, but has a configuration in which an automatic shift can be achieved by being combined with an actuator (gear shift unit, GSU) 84 here.

The actuator 84 operates the air supply means 8 by switching the solenoid valve 85 by the control unit 79.
The air conditioner 6 is operated by appropriately supplying air to execute a shift operation. The air supply means 86 includes an air tank 88 connected to the engine compressor 87,
An air pipe 90 is provided with a relief valve 89 interposed therebetween. The tip of the air pipe 88 is connected to a solenoid valve 85 of an actuator 84. The air tank 88 is provided with a pressure switch 91 connected to the control unit 79.

In addition, the transmission 75 is provided with a vehicle speed sensor 92 and an input shaft rotation sensor 93, each of which is connected to the control unit 79. The input side of the control unit 79 is connected to an accelerator sensor 94, a change lever 95, and an emergency manual switch 96 capable of shifting all steps, and the output side is connected to a gear indicator light 97 and a warning light 98. A control unit 102 for exchanging signals is provided alongside the control unit 79, and the fuel injection pump 10 is controlled based on a detection value of an engine rotation sensor 103 and the like.
4 to control the electronic governor 105.

FIG. 2 is a detailed view showing the clutch torque converter unit 50. The clutch torque converter unit 50 is mainly configured by combining a main clutch 52 and a torque converter 53. The main clutch 52 is configured as a hydraulically controlled wet multi-plate clutch. Here, a lock-up clutch 71 for locking the torque converter 53 is also provided, and the lock-up clutch 71 also employs a hydraulically controlled wet multi-plate clutch as described above. As will be understood later, the torque converter 53 and the main clutch 52 are in a serial relationship from the engine side, and the torque converter 53 and the lock-up clutch 71 are in a parallel relationship from the engine side. Hereinafter, these configurations will be specifically described.

In FIG. 2, reference numeral 54 denotes an input shaft to which engine power is input. The input shaft 54 has a front cover 6
7 and the torque converter housing 68 are integrally connected. On the other hand, the torque converter 53 is constituted by a three-element wheel, and a torque converter housing 68
And a turbine unit 59 facing the pump unit 58, and a one-way clutch 6
0 and a stator portion 61 provided through the same. Therefore, in the torque converter 53, when the input shaft 54 is rotated, the pump portion 58 is rotated, and this circulates oil as a working fluid around the input shaft 54, and drives the turbine portion 59 to rotate. Generate.
In addition to the circulation around the input shaft 54, the oil is also circulated in an orthogonal direction such that the oil passes through the pump section 58, the turbine section 59, and the stator section 61 in this order. Note that the torque converter 53 is disposed closer to the transmission 75 than the main clutch 52 is.

On the other hand, in a space surrounded by the front cover 67 and the torque converter housing 68, the main clutch holder 64 and the main clutch piston outer holder 65 connected to each other are connected to the output shaft via the bearing 63 and the clutch holder 62. 56 is supported rotatably around its axis. The output shaft 56 is arranged coaxially with the input shaft 54, and the transmission 75
Of the input shaft. Clutch holder 6
2 is attached to the output shaft 56 via a spline (not shown) so as not to rotate relatively. The main clutch piston outer holder 65 is slidable and rotatable on the inner surface of the front cover 67, and is not movable in the axial direction. Since the turbine portion 59 of the torque converter 53 is rigidly connected to the main clutch holder 64, the turbine portion 59 can rotate around the output shaft 56.

The main clutch 52 disconnects and connects the turbine section 59, that is, the output side of the torque converter 53, with the output shaft 56. That is, the main clutch 52 has a plurality of drive plates 55 attached to the main clutch holder 64 via splines so as to be movable in the axial direction, and a plurality of driven plates attached to the clutch holder 62 via splines so as to be movable in the axial direction. 57. These plates 55 and 57 are arranged so as to alternately overlap. The main clutch piston outer holder 65 has a cylinder chamber 66 formed therein.
Accommodates a main clutch piston 51 movably in the axial direction. Therefore, hydraulic pressure is supplied to the cylinder chamber 66, and the main clutch piston 51 is moved to the plates 55 and 57.
By moving to the side, the plates 55 and 57 are brought into frictional contact with each other, and the main clutch 52 can be brought into the engaged state. Then, the output side of the torque converter 53 and the output shaft 56 can be connected.

On the other hand, a lock-up clutch 71 of the same construction is disposed radially outside the main clutch 52. The lock-up clutch 71 is for directly connecting the pump unit 58 and the turbine unit 59 of the torque converter 53. That is, the lock-up clutch 71 includes a plurality of drive plates 73 provided on the torque converter housing 68 via splines so as to be movable in the axial direction, and a driven clutch provided on the main clutch holder 64 via the splines so as to be movable in the axial direction. And a plate 72. Cylinder chamber 99 of front cover 67
Accommodates a lock-up clutch piston 74 movably in the axial direction. Therefore, by applying hydraulic pressure to the piston 74, the plates 73, 72 are brought into frictional contact with each other to bring the lock-up clutch 71 into the engaged state, so that the torque converter 53 can be locked.

Here, on the transmission side of the torque converter 53, an oil pump (not shown) interlocked with the torque converter housing 68 is provided.
After the generated hydraulic pressure is controlled to a predetermined value by a hydraulic supply device as shown in FIG.
9, the desired clutch engagement force is generated.
In FIG. 1, electromagnetic switching valves 77 and 78 for switching supply and discharge of hydraulic pressure to and from the cylinder chambers 66 and 99 are shown.

The main clutch 52, the lock-up clutch 71, and the torque converter 53 use a common oil as a working fluid. That is, the space surrounded by the front cover 67 and the torque converter housing 68 is filled with the common oil. This oil is sent to each cylinder chamber 66, 99 by a separate system as shown in FIG.
Also used for control. When the temperature of the oil is low and the viscosity is high, the drag between the plates 55, 57, 72, 73 in the main clutch 52 and the lock-up clutch 71 becomes strong. Also, the oil flow in the control system is deteriorated, and the control response tends to be deteriorated as a whole.

In FIG. 1, reference numeral 80 denotes an oil cooler for cooling oil at a high temperature. The oil cooler 80 is connected to the clutch torque converter unit 50 via a pipe 81. A temperature sensor 82 and a pressure sensor 8
The control unit 79 manages oil temperature and oil pressure.

This power transmission device has the following advantages.
Since the torque converter 53 can be used at the time of starting, complicated half-clutch control of the main clutch 52 becomes unnecessary. The contact shock during shifting can be absorbed by the torque converter 53. Since the manual transmission 75 is used, a wide range of gear ratio selections is possible and a long-lasting gear ratio can be set as compared with a torque converter automatic transmission system using planetary gears. The service life of the clutch can be extended. Since it is combined with a transmission having an automatic transmission mechanism (actuator 84), it can be used as an A / T. In addition, when combined with a normal manual transmission, it can be used as an M / T.
Since the torque converter 53 is used at the joint with the engine 76, noise and vibration of the drive system can be reduced.

Next, the operation of this power transmission device is actually as follows. First, it is assumed that the driver operates the change lever 95 for shifting. The change lever 95 is like an electric switch, and only issues a shift instruction signal to the control unit 79 as to what speed should be set next. Then, the control unit 79 receives the shift instruction signal and starts the disconnection of the main clutch 52. That is, the shift instruction signal is the clutch disconnection start signal according to the present invention. The disconnection of the main clutch 52 is performed by switching the electromagnetic switching valve 77 of the hydraulic pressure supply device to the supply side. Thus, the hydraulic pressure is sent to the cylinder chamber 66, and the main clutch 52 is disconnected. The fact that the clutch has been disconnected is detected by the control unit 79 in a manner described later.

After that, the control unit 79 switches the electromagnetic valve 85 so that the transmission 75 is shifted to the next gear position based on the previous shift instruction signal. When the shift is completed, the electromagnetic switching valve of the hydraulic pressure supply device is switched to the discharge side, the hydraulic pressure in the cylinder chamber 66 is discharged, and the main clutch 52 is connected. Thus, a series of speed change operations is completed.

On the other hand, in this device, the engine 76 is electronically controlled as follows. That is, the control unit 79
Reads the engine load based on the output of the accelerator sensor 94 and the engine speed based on the output of the engine rotation sensor 103, and determines the target fuel injection amount mainly based on these values. Then, the control unit 102 outputs predetermined electric power corresponding to the target fuel injection amount, controls the electronic governor 105, and controls the fuel injection amount.

However, when the main clutch 52 is disengaged, independent engine control is performed irrespective of whether the driver depresses the accelerator pedal.

That is, the following control is performed when the main clutch 52 is disconnected. As shown in FIG. 3, when the control unit 79 receives a shift instruction signal (clutch disengagement start signal) from the change lever 95 in step 1, it causes the control unit 79 to maintain the engine rotation at the received engine speed in step 2 in step 2. Executing the engine control. In the next step 3, the control unit 79
From the output of the engine speed sensor 103, the engine speed Ne
Is read from the output of the input shaft rotation sensor 93 at predetermined time intervals, and a difference ΔN between the rotation speeds is calculated at predetermined time intervals. Then, the rotational speed difference ΔN is compared with a preset value N stored in advance, and the engine rotation holding control in step 2 is continued until ΔN ≧ N. If ΔN ≧ N, the routine proceeds to step 4, where the engine rotation holding control is released and the control returns to the normal engine control.

Next, a comparison between this control and the conventional control will be made.
FIG. 4 shows how the engine speed and the input shaft speed change when upshifting is performed during traveling at a predetermined gear position. The engine speed by this control is N
e (dot-dash line), the engine speed under the conventional control is Ne
x (broken line), input shaft speed is Ni (solid line)
Indicated by Here, since the driver usually returns the accelerator pedal simultaneously with the operation of the change lever 95 (this operation is referred to as T ₁ ), conventionally, the engine speed Nex is set to the time T
It drops uniformly from ₁ .

On the other hand, although the clutch divided by the time T ₁ is started, generally, if indeed clutch expires, should the input shaft rotation speed falls from the engine rotational speed. Therefore, the determination as to whether or not the clutch has been released is made by comparing the rotation speed difference between the engine rotation speed and the input shaft rotation speed with the set value, as described above. However, since the wet multi-plate clutch tends to rotate with the clutch, conventionally, when the two rotation speeds Nex and Ni are similar in dropping manner, it is relatively long to obtain a rotation speed difference ΔN equal to or more than the set value N. It took time ΔTx. In other words, even if the pressing force of the clutch plate is released, the driven plate follows the drive plate due to the viscosity of the oil, so that the power cannot be actually transmitted, that is, it is determined that the clutch is engaged even though the clutch is disconnected. It will do.

[0033] Therefore, in this control, as shown in dashed line, and from time T ₁ to hold the engine rotation. In this case, the engine speed does not drop, and a speed difference ΔN equal to or larger than the set value N can be obtained in a relatively short time ΔT,
Clutch disconnection can be detected. That is, since the engine rotation is forcibly maintained so as to separate the drive plate from the driven plate whose rotation is about to drop, the rotation of the driven plate is prevented, and the clutch disconnection can be detected early. In this way, the control response of the clutch can be greatly improved, and a series of shift times can be shortened.

In particular, this control is effective at low oil temperature where the tendency of clutch rotation is strong, especially immediately after starting at low temperature.
However, as described above, when the number of revolutions after clutch disengagement is similar, it is effective even at high oil temperature. The time required to disengage the clutch is, for example, 0 for large commercial vehicles.
Since it is as short as 1 to 0.15 seconds, even if the engine rotation holding control is performed in this time, the driver feels only as if the engine is stuck, and there is no problem in feeling. Incidentally control unit 79 performs the engine rotation holding control engine speed at time T ₁ as a target rotational speed, the actual engine speed does not become completely constant for inertia.

As can be seen from the above description, in the present apparatus,
The main clutch 52, the engine rotation sensor 103, the input shaft rotation sensor 93, the change lever 95, and the control unit 79 are respectively a wet multi-plate clutch of the present invention, first detection means, second detection means, signal generation means, control means. Is composed.

Here, in the present apparatus, the clutch disconnection detection is performed by using the engine speed and the input shaft speed. However, it is only necessary to look at the input and output speeds of the clutch. Can also be used. For example, the rotation speed of the front cover 67 may be detected by the pulse sensor 25 shown in FIG. 1 and used as the clutch input side rotation speed. Further, here, the present invention is applied to a combination of the main clutch 52 as a wet type multi-plate clutch and the torque converter 53, but the type and the type of the device are not limited as long as the device is provided with the wet type multi-plate clutch. Further, the present invention can be applied not only to the transmission capable of automatic transmission as described above, but also to an apparatus having a normal manual transmission.

In addition, various other embodiments of the present invention are conceivable.

[0038]

The present invention exhibits the following excellent effects.

(1) The rotation of the clutch can be prevented, and the clutch disconnection can be detected early.

(2) The clutch control response can be greatly improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a power transmission device according to the present invention.

FIG. 2 is a longitudinal sectional view showing a clutch torque converter unit.

FIG. 3 is a flowchart showing control contents when the main clutch is disconnected.

FIG. 4 is a time chart showing how the engine speed and the input shaft speed change when the main clutch is disconnected.

FIG. 5 is a longitudinal sectional view of a wet multi-plate clutch.

FIG. 6 is a hydraulic circuit diagram of the hydraulic supply device.

[Explanation of symbols]

 52 main clutch 75 transmission 76 engine 79 control unit 93 input shaft rotation sensor 95 change lever 103 engine rotation sensor N set value Ne engine rotation speed Ni input shaft rotation speed ΔN rotation speed difference

Claims (1)

[Claims] 1. A vehicle power transmission device for transmitting power of an engine to a transmission via a wet multi-plate clutch, comprising: first detection means for detecting an input side rotation speed of the clutch; Second detecting means for detecting the output rotation speed of the clutch, signal generating means for generating a clutch disconnection start signal, and disconnection of the clutch when a clutch disconnection start signal is received from the signal generating means. And control means for holding the engine rotation until the clutch input / output side rotational speed difference calculated based on the outputs of the first and second detection means reaches a predetermined value. Power transmission device for a vehicle.