JPH0332936A - Power transmission for vehicle - Google Patents

Abstract

PURPOSE:To guarantee normal operation of ABS, in a four wheel drive vehicle, by providing a valve means at a relief hole for relieving a main flow passage of a hydraulic pump driven by difference in rotation speed between two rotation members which are capable of relative rotation and by controlling it according to a wheel slip state. CONSTITUTION:A driven sprocket 7 is rotatably supported by a rotor 1, a front drive shaft, and connected to a drive sprocket through a chain 9 so as to freely transmit power. A plurality of plunger chambers 16 are formed in the axial direction in this rotor 1, and each of them is engaged with a plunger 17 and each of the plunger 17 is brought into contact with and slide on a cam surface 18A of a cam housing 18 so as to function as a hydraulic pump driven by difference in rotation speed between 1 and 18. A main passage 27 is formed at the center part of the rotor 1 and communicated with a high pressure chamber 29 communicating with a discharge passage 24 through a relief hole 84. The relief hole 84 is opened and closed by a valve means 38 controlled according to comparison results between the difference in rotation speed of front and rear wheels and a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power transmission device for a vehicle having a hydraulic power transmission joint.

[Prior Art] As a conventional power transmission device for a vehicle, for example, Japanese Patent Application Laid-Open No. 61
There is one described in JP-249628.

This device increases the drive torque to the rear wheels when the front wheels slip when braking the vehicle to avoid the vehicle becoming unable to drive, and increases the brake torque to the front wheels when the rear wheels tend to lock up. This is to prevent the rear wheels from locking up.

In addition, Japanese Utility Model Publication No. 63-22233 discloses a brake pedal switch that is equipped with a shuttle valve that opens an auxiliary passage to allow relative rotation of two rotating shafts when the brake pedal switch detects that the brake pedal is depressed. It is written that the side wheels should lock before the rear wheels.

[Problem to be Solved by the Invention] However, in the former case, in such a conventional vehicle power transmission device, when the brakes are strongly applied, such as when suddenly braking, all wheels are locked at the same time. Even if an anti-skid brake (hereinafter referred to as ABS) is installed, the approximate vehicle speed cannot be detected from the unlocked wheels, resulting in the problem that the ABS cannot be operated properly. .

In the latter case, when the brake pedal is pressed, the brake switch will operate regardless of how the brake pedal is pressed, and the actuator (solenoid valve, etc.) will operate.
Since the actuator operates frequently, there are problems in that the durability of the actuator is significantly reduced, power consumption is increased, and the battery becomes dead.

The present invention has been made in view of these conventional problems, and provides a power transmission device for a vehicle that enables normal operation of ABS and improves the durability and reliability of the actuator. is intended to provide.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a hydraulic pump driven by a rotational speed difference between a first rotating member and a second rotating member that are relatively rotatable. , a hydraulic power transmission joint having a variable orifice mechanism provided in a discharge path of the hydraulic pump, a relief hole for relieving hydraulic oil from the hydraulic pump, and a valve means for opening and closing the relief hole; and a front wheel rotation sensor. Based on the input of the front wheel rotation speed signal from the rear wheel rotation sensor, the rear wheel rotation speed signal from the rear wheel rotation sensor, and the accelerator pedal switch signal from the accelerator pedal switch, it is determined whether the accelerator pedal switch signal is on or off, and the difference in front and rear wheel rotation speeds is determined. The vehicle is equipped with control means for determining the front and rear wheel rotational speed difference with a predetermined value, and controlling the opening and closing of the valve means based on the comparison result.

[Operation] In the present invention, when the accelerator pedal is depressed and the rotational speed difference between the front and rear wheels is greater than or equal to a predetermined value, it is assumed that the front wheels or rear wheels are locked or the brakes are being depressed just before they are locked. Judging, turn on the solenoid coil 2
The vehicle is set to WD, and when the accelerator pedal is depressed, the solenoid coil is turned off to set the vehicle to 4WD.

In the 2WD driving state, all wheels do not lock at the same time, allowing ABS to operate normally, and ABS can be used even in 4WD vehicles equipped with hydraulic power transmission joints.

In addition, since the actuator is activated only under limited braking conditions near the activation of ABS, the durability and reliability of the actuator can be improved, power consumption can be significantly reduced, and battery drain can be prevented. be able to.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 to 4 are diagrams showing one embodiment of the present invention, which is applied to a vehicle based on a rear wheel drive vehicle.

First, to explain the configuration, in Fig. 2, 1 is the front drive shaft (first rotating member) which is the output shaft (
The rotor 1 is rotatably supported by the casings 2 and 3 via bearings 4.5.

A driven sprocket 7 is rotatably supported on the rotor 1 via a needle bearing 6, and a chain 9 is installed between the driven sprocket 7 and the drive sprocket 8. In addition, 10 is an output flange, 11 is a nut, 12.13 is an oil seal, 14 is a stop ring, and 5 is a thrust washer.

A plurality of plunger chambers 16 are formed in the rotor 1 in the axial direction, and a plurality of plungers 17 that reciprocate in the axial direction are housed in the plunger chamber 16. A cam surface 18A is formed on the inner surface of a cam housing (second rotating member) 18 fixed to the driven sprocket 7, and the plunger 17 is in sliding contact with the cam surface 18A. Note that the plunger 17 and the plunger chamber 16 collectively constitute a hydraulic pump.

19 is a suction passage communicating with the plunger chamber 16, and a suction valve 20 is interposed in the suction passage 19. That is,
The suction valve 20 is provided coaxially with the plunger chamber 16 and at the bottom. A return spring 21 holds the suction valve 20, and a plug 22 holding the return spring 21 is held by the return spring 23 of the plunger 17.

Reference numeral 24 denotes a discharge passage that opens in the side wall of the plunger chamber 16 and is formed toward the center of the rotor 1. A discharge valve 25 is interposed in the discharge passage 24 via a return spring 26.

Further, 81 is a needle pulp (variable orifice mechanism) movably stored in the storage hole 82 of the plug 31, and 83 is an orifice whose opening area is variable by the needle pulp 81.

Further, a main passage 27 is formed in the center of the rotor 1, and the main passage 27 is connected to the discharge passage 24 through the relief hole 84.
The high pressure chamber 29 communicates with the high pressure chamber 29 .

Further, the main passage 27 communicates with the suction passage 19 via a passage 30 formed in the rotor 1.

Further, 31 is a plug that holds the return spring 26, 32 is a piston, and 33 is a spring that holds the piston 32. Also, 34°35 is an oil seal,
36 is a stop ring, and 37 is a thrust washer.

Reference numeral 38 denotes a valve means for opening and closing the relief hole 84, and the valve means 38 is composed of a non-magnetic cylinder 39 and a needle pulp 40 housed within the cylinder 39 and made of a movable magnetic material. The needle pulp 40 has a communication hole 41 formed therein and is biased by a return spring 42 .

A magnetic frame 43 is fixed to the casing 3 and forms a magnetic circuit. The magnetic frame 43 is held in a non-contact state by the non-magnetic cylinder 39 inside the rear end of the needle pulp 40, and has a solenoid coil 44 inside. is stored. In addition, 46
is a cover provided on the magnetic frame 43.

Next, the arrangement of the joints is shown in FIG.

In FIG. 1, 51 is an engine, 52 is a transmission, and 53 is a transfer.

A main shaft 54 is rotatably supported by the casings 2 and 3 through bearings within the transfer 53, and the main shaft 54 is provided with a drive sprocket 8. A driven sprocket 7 connected to a drive sprocket 8 by a chain 9 is rotatably supported by a rotor l via a needle bearing 6. The rotor l has the aforementioned joint 57 incorporated therein. In addition,
58 is a right front wheel, 59 is a left front wheel, 60 is a right rear wheel, 61 is a left rear wheel, 62 is a front wheel side differential gear device, 63 is a rear wheel side differential gear device, 64 is a front wheel side propeller shaft, 65 is a rear wheel This is the side propeller shaft.

Reference numeral 71 denotes a front wheel rotation sensor provided near the rotor 1. The front wheel rotation sensor 71 detects a front wheel rotation speed NF and sends a front wheel rotation speed signal to a controller (control means) 72. Reference numeral 73 denotes a rear wheel rotation sensor provided near the cam housing 8. The rear wheel rotation sensor 73 detects the rear wheel rotation speed NR and sends a rear wheel rotation speed signal to the controller 72.

74 is an accelerator pedal switch provided near the accelerator pedal 75. The accelerator pedal switch 74 detects depression of the accelerator pedal 75 and sends an on/off signal to the controller 72.

The controller 72 determines the front and rear wheel rotational speed difference ΔN from the front wheel rotational speed signal and the rear wheel rotational speed signal, and sets the set value ΔN.
It compares this with No and also determines whether the accelerator pedal 75 is on or off based on the accelerator pedal switch signal, and outputs a control signal to the solenoid coil 44.

Next, the effect will be explained.

FIG. 3 shows a control flowchart of the present invention.

In FIG. 3, first, initial values are set in step S1. That is, a predetermined front and rear wheel rotational speed difference ΔNo is set. Next, in step S2, the front wheel rotation speed (NF) signal is sent from the front wheel rotation sensor 71, the rear wheel rotation speed (NR) signal is sent from the rear wheel rotation sensor 73, and the accelerator pedal switch 7
4, the accelerator pedal switch signals are respectively input as data.

Next, in step S3, the front and rear wheel rotational speed difference ΔN (ΔN=N
F-NR) is calculated by the controller 72.

Next, in step S4, it is determined whether or not the accelerator pedal switch 74 is off, and if it is off, the process advances to step S5. Note that instead of the accelerator pedal switch 74, a signal from a sensor that detects the intake negative pressure of the engine, a throttle opening sensor, or the like may be determined. In step S5, it is determined whether or not the front and rear wheel rotational speed difference ΔN exceeds a predetermined value ΔNO. If ΔN>ΔNo, the solenoid coil 44 is turned on in step S6.

That is, when the accelerator pedal switch 74 is off and the difference in rotational speed between the front and rear wheels ΔN exceeds the predetermined value ΔNO, it is determined that the front or rear wheels are locked or the brake is being applied just before locking, and the solenoid is activated. Turn on coil 44.

When the solenoid coil 44 is turned on, the needle valve 40 moves to the right against the return spring 42 to open the relief hole 84.

Therefore, the vehicle enters a free state as shown in E in FIG. 4, that is, 2WD.

In this 2WD driving state, all wheels do not lock at the same time, so ABS operates normally.

Further, since the solenoid coil 44 is turned on only under limited braking conditions near the activation of ABS, it is possible to improve the durability and reliability of the actuator and reduce power consumption.

On the other hand, when the accelerator pedal switch 74 is turned on in step S4, the solenoid coil 44 is turned off in step S7.

When the solenoid coil 44 is turned off, the needle valve 40 is biased by the return spring 42 and moves to the left to close the relief hole 84. Therefore, 4
The vehicle enters a WD running state and has normal characteristics determined by the orifice 83.

Note that when the discharge pressure P reaches Pl, the orifice 83 is closed by the needle valve 81 and becomes locked (
When the discharge pressure P reaches P2, the needle valve 40 constituting the valve means 38 moves to the right against the return spring 42 to open the relief hole 84, resulting in a relief characteristic (see FIG. 4, 81). (See Figure 4 C1).

[Effects of the Invention] As explained above, according to the present invention, ABS can be operated normally even in a four-wheel drive vehicle equipped with a hydraulic power transmission joint, so ABS can be adopted.
In addition, since the actuator is activated only under limited braking conditions near ABS activation, the durability and reliability of the actuator can be greatly improved, power consumption can be significantly reduced, and battery drain can be prevented. be able to.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view of a hydraulic power transmission joint, FIG. 3 is a control flowchart, and FIG. 4 is a graph showing torque characteristics. In the figure, ■... Rotor (first rotating member), 2.3... Casing, 4.5... Bearing, 6... Needle bearing, 7... Driven sprocket, 8... Drive sprocket, 9... Chain, 10... Output flange, 11... Nut, 12.13... Oil seal, 14... Stop ring, 5... Thrust washer, 6... Plan Jar chamber, 7... plunger 8... cam housing (second rotating member) 8A...
Cam surface, 9...Suction path, 0...Suction valve, 1...Return spring, 2...Plug, 3...Return spring, 4...Discharge path, 5...Discharge valve , 6... Return spring, 7... Main passage, 9... High pressure chamber, 0... Passage, 1... Plug, 2... Piston, 33... Return spring, 34.35 ...Oil seal, 36...Stop ring, 37...Thrust washer, 38...Valve means, 39...Cylinder body, 40...Needle pulp, 41...Communication hole, 42... ...Return spring, 43...Magnetic frame, 44...Solenoid coil, 46...Cover 51...Engine, 52...Transmission, 53...Transfer 54...Main shaft, 57... ...Joint, 58...Right front wheel, 59...Left front wheel, 60...Right rear wheel, 61...Left rear wheel, 62...Rear side differential gear device, 63...
- Rear wheel side differential gear device, 64... Front wheel side propeller shaft, 65... Rear wheel side propeller shaft, 71... Front wheel rotation sensor, 72... Controller (control means), 73... Rear Wheel rotation sensor, 74... Accelerator pedal switch, 75... Accelerator pedal, 81... Needle pulp 82... Storage hole, 83... Orifice, 84... Relief hole. (variable orifice mechanism)

Claims (1)

[Claims] (1) A hydraulic pump driven by a rotational speed difference between a first rotating member and a second rotating member that are relatively rotatable, a variable orifice mechanism provided in a discharge path of the hydraulic pump, and the hydraulic pump a hydraulic power transmission joint having a relief hole for relieving hydraulic oil from the hydraulic power transmission joint, a valve means for opening and closing the relief hole, a front wheel rotation speed signal from a front wheel rotation sensor, and a rear wheel rotation speed signal from a rear wheel rotation sensor. and determining whether the accelerator pedal switch signal is on or off by inputting the accelerator pedal switch signal from the accelerator pedal switch, determining the front and rear wheel rotational speed difference, and comparing the front and rear wheel rotational speed difference with a predetermined value, A power transmission device for a vehicle, comprising a control means for controlling opening and closing of the valve means based on a comparison result.