JP2002114050A - Parking brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the safety and reliability of a parking brake in a vehicle provided with a third differential device absorbing the rotation difference generated between a front driving shaft and a rear driving shaft. SOLUTION: This parking brake device is provided with a relay emergency valve 38 feeding or discharging the operating pressure of the differential gear lock mechanism 35 of a third differential device according to the feed or discharge of the pressure by the hand-controlled valve 32 of a parking spring brake as a means for interlocking the differential gear lock mechanism of the third differential device with a parking wheel brake to keep the third differential device at a differential gear lock state during the operating state of the parking wheel brake.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a parking brake device for a vehicle.

[0002]

2. Description of the Related Art A parking brake device for a vehicle is mainly intended to prevent the vehicle from moving during parking or the like, and various mechanisms (for example, a spring brake) for assisting a parking brake are known. I have.

[0003]

SUMMARY OF THE INVENTION The present invention is based on the prior art described above, and utilizes a differential lock mechanism of a third differential device provided between drive shafts in a two-shaft drive vehicle to park the vehicle. The aim is to increase the safety and reliability of the brake. Incidentally, Japanese Patent Application Laid-Open No. 5-38962
And JP-A-7-32917 disclose a third differential (inter-differential mechanism) and a differential lock mechanism thereof.

[0004]

According to a first aspect of the present invention, there is provided a vehicle including a third differential that absorbs a rotational difference generated between a front drive shaft and a rear drive shaft. Means for interlocking the differential lock mechanism of the third differential with the parking wheel brake in order to maintain the third differential in the differential lock state.

According to a second aspect of the present invention, in a vehicle provided with a third differential that absorbs a rotation difference generated between a front drive shaft and a rear drive shaft, the supply and discharge of pressure by a hand control valve of a parking spring brake are performed. A relay emergency valve for supplying and discharging the operating pressure of the differential lock mechanism of the third differential device accordingly.

According to a third aspect of the present invention, in a vehicle including a third differential that absorbs a rotation difference generated between a front drive shaft and a rear drive shaft, the operating pressure of a differential lock mechanism of the third differential is supplied and discharged. ON-OF according to the indicator light switch of the parking wheel brake to energize the magnetic valve
F relay is provided.

According to a fourth aspect of the invention, in a vehicle including a third differential that absorbs a rotational difference generated between a front drive shaft and a rear drive shaft, an operating pressure of a differential lock mechanism of the third differential is supplied. A magnetic valve that has a solenoid that switches the valve to a position that discharges the operating pressure as well as a solenoid that switches the valve to the position, and selectively energizes the two solenoids of the magnetic valve according to the indicator light switch of the parking wheel brake ON relay
It is characterized by having.

[0008]

According to the first to fourth aspects of the present invention, when the parking wheel brake is in operation, the front drive shaft and the rear drive shaft are directly connected by the operation of the differential lock mechanism of the third differential. Is done. Therefore, unless the wheels of the front drive shaft rotate, the wheels of the rear drive shaft also do not rotate. Therefore, depending on the road surface condition (the coefficient of road surface friction and the magnitude of the road surface gradient), for example, the front drive shaft wheels are likely to slip. In this case, the wheel brake acting on the wheels of the front drive shaft is transmitted to the road surface via the wheels of the rear drive shaft. If the differential lock mechanism of the third differential does not operate in the parking brake operating state, the wheels of the rear drive shaft can roll on the road surface if the wheels of the front drive shaft slide on the road surface (the wheel brakes are not transmitted to the road surface). However, by linking the differential lock mechanism to the parking brake, it is possible to improve the safety and reliability of the parking brake against such a possibility.

In the fourth invention, when the parking wheel brake is actuated, the indicator lamp switch is turned on, and of the two solenoids of the magnetic valve,
Current is supplied via a relay to a solenoid that switches the valve to the supply side, and the differential lock mechanism of the third differential operates, while when the parking wheel brake is released, the indicator lamp switch turns off, and the opposite of the magnetic valve Current is supplied to the solenoid on the side (switching the valve to the discharge side) via a relay, and the differential lock mechanism of the third differential device is released. In the operating state of the parking brake, even if the power to the relay is cut off, the magnetic valve does not switch (the two solenoids are in the inoperative state), so that the differential lock mechanism of the third differential can be maintained in the operating state. It is.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the rear two-shaft drive vehicle shown in FIG.
Reference numerals a and 2b denote wheels of the rear front shaft 2 (drive shaft), 3a and 3b denote wheels of the rear rear shaft 3 (drive shaft), and 1a and 2b denote front shafts (driven shafts).
Wheels, 8a and 8b are parking brakes (wheel park)
Spring brake for the rear front axle 2
a, 2b. 4 is a prime mover (engine) of the vehicle, 5 is a first differential that absorbs a rotational difference generated between the wheels 2a and 2b of the rear front shaft 2, and 6 is wheels 3a and 3 of the rear rear shaft 3.
b is a second differential that absorbs a rotational difference generated between b and 7 is a third differential (inter differential mechanism) that absorbs a rotational difference generated between the rear rear shaft 2 and the rear rear shaft 3; The output of the engine 4 is transmitted to the propeller shaft via a clutch and a transmission (not shown), and is further distributed from the third differential 7 to the first differential 5 and the second differential 6.

FIG. 2 is a diagram showing the configuration of the third differential device 7, in which a spider shaft 11 forming an orthogonal axis in a differential case 10 is shown.
, A plurality of pinion gears 12 are rotatably supported. A front differential gear 13 meshes with the pinion gear 12 on the front side, and a through shaft 14 is spline-fitted to the differential gear 13. The rear differential gear 15 meshes with the pinion gear 12 on the rear side, and a divider gear 16 rotatably supported on the through shaft 14 is spline-fitted to the rear differential gear 15. Drive pinion 17 meshing with ring gear 5a of first differential device 5
Are spline-fitted to a pinion drive gear 18 meshing with the divider gear 16. The drive pinion 19 that meshes with the ring gear 6 a of the second differential 6 is connected to the through shaft 14 via a universal joint 20.

A propeller shaft is connected to a companion flange of the differential case 10, and rotation input to the differential case 10 is transmitted to a front differential gear 13 and a rear differential gear 15 via a pinion gear 12 that revolves integrally with the spider shaft 11. The rotation of the front differential gear 13 is transmitted to the ring gear 6a of the second differential 6 via the through shaft 14 and the universal joint 20 and the drive pinion 19, while the rotation of the rear differential gear 15 is divided by the divider gear 16 and the pinion drive gear 18 and First via drive pinion 17
The power is transmitted to the ring gear 5 a of the differential device 5.

Between the rear front shaft 2 and the rear rear shaft 3 (the ring gear 5a of the first differential 5 and the ring gear 6a of the second differential 6)
), The rotation difference is absorbed by the rotation of the pinion gear 12 (rotation about the spider shaft 11). A sliding clutch 21 is provided to stop (diff lock) this differential action. The sliding clutch 21 is spline-fitted to the through shaft 14, and when shifting to the divider gear 16 during differential lock, a part of the
, The through shaft 14 and the divider gear 16 are integrally connected.

In FIG. 3, the parking spring brakes 8a and 8b have a chamber 30 containing a spring. The spring brake chamber 30 is connected to a tank 33 via a relay valve 31. Relay valve 3
When the pressure (compressed air) for closing the discharge port is guided from the hand control valve 32 (linked to the side lever in the cab), the pressure from the tank 33 is changed to the chamber 3.
When the pressure closing the outlet is discharged from the hand control valve 32, the pressure of the chamber 30 is released from the outlet while the spring is kept in a compressed state (spring brake inoperative state). Activate the spring brake.

Reference numeral 35 denotes a differential lock mechanism of the third differential device 7, which is provided with an actuator 35a (a diaphragm device, an air cylinder, or the like) for shifting the sliding clutch 21 (see FIG. 2). Actuator 35
a, when the pressure (compressed air) of the tank 37 is supplied from the magnetic valve 36, the sliding clutch 2
1 is shifted to a differential lock position (a position connecting the through shaft 14 and the divider gear 16), and when the pressure is released from the magnetic valve 36, the sliding clutch 21 is returned to the initial position (the through shaft 14, the divider gear 16 and the divider gear 16) by the return spring. (The position at which the connection of the two is released).

The magnetic valve 36 supplies the pressure from the tank 37 to the actuator 35a when the power supply to the solenoid is turned on, and discharges the pressure from the actuator 35a when the power supply to the solenoid is turned off. . The solenoid of the magnetic valve 36 is wired to the battery 42 via a differential lock switch 40 in the operator's cab and an ignition switch 41 in series therewith. That is, only when the ignition switch 41 is ON and the differential lock switch 40 is ON, the power supply to the solenoid of the magnetic valve 36 is turned ON.

In the differential lock circuit, a relay emergency valve 38 for supplying and discharging the pressure of the actuator 35a is provided in parallel with the magnetic valve 36. The relay emergency valve 38 is used to link the differential lock mechanism 35 of the third differential device 7 to a hall park (parking brake). In FIG. 3 (first embodiment), the hand control of the spring brake is performed. When the pressure for opening the outlet from the valve 32 is released, the outlet is closed to supply the pressure from the tank 37 to the actuator 35a of the differential lock mechanism 35, while the pressure for opening the outlet from the hand control valve 32 (compressed air). Is released, the pressure of the actuator 35a is released from the discharge port. A double check valve 39 selectively connects the relay emergency valve side 38 and the magnetic valve 36 side to the actuator 35a.

With this configuration, when the side lever of the cab is operated toward the parking brake operation side, the pressure for closing the discharge port of the relay valve 31 and the pressure for opening the discharge port of the relay emergency valve 38 are changed from the hand control valve 32. When opened, the relay valve 31 releases the pressure of the spring brake chamber 30 from the discharge port, while the relay emergency valve 38 supplies the pressure to the actuator 35 a of the differential lock mechanism 35. Therefore, the differential lock mechanism 35 of the third differential device 7 operates in conjunction with the operation of the spring brake.

In the operating state of the parking brake, the rear front shaft 2 and the rear rear shaft 3 are directly connected by the sliding clutch 21 of the third differential device 7, and the wheels 2a, 2a of the rear front shaft 2 are connected.
The spring brake acting on 2b is transmitted to the rear rear shaft 3 via the third differential device 7. Therefore, even if the wheels of the rear front shaft 2 are likely to slip due to the road surface condition (the coefficient of road surface friction or the magnitude of the road surface gradient), unless the wheels 2a and 2b of the rear front shaft 2 rotate, the rear rear shaft 2 may be rotated. Since the wheels 3a and 3b of the shaft 3 also do not rotate, the spring brake acting on the wheels 2a and 2b of the rear front shaft 2 is transmitted to the road surface via the wheels 3a and 3b of the rear rear shaft 3.

When the differential lock mechanism 35 of the third differential device 7 does not operate, if the wheels 2a and 2b of the rear front shaft 2 slide on the road surface (spring brake is not transmitted to the road surface) in the parking brake operating state, the rear position is changed. Wheels 3a, 3b of rear shaft 3
It is conceivable that the vehicle may roll on the road surface. However, as described above, by linking the differential lock mechanism 35 of the third differential device 7 with the parking brake, the safety and reliability of the parking brake against such a possibility can be considered. Is obtained.

FIG. 4 shows a second embodiment.
Reference numeral 30a denotes a spring brake chamber of a parking brake (wheel park), the pressure of which is supplied / discharged via a hand control valve 32a (linked to a side lever in the cab). Reference numeral 50 denotes an indicator lamp for displaying the operating state of the spring brake. The indicator lamp 50 is lit by receiving the battery current only when the ignition switch 51 is ON and the indicator lamp switch 41 is ON. The indicator lamp switch 51 is a pressure switch that is turned off (contact is opened) by the pressure of the spring brake chamber 30a, and is turned on (contact is closed) when the pressure of the spring chamber 30 is discharged from the hand control valve 32a.

A normally open type relay 52 is interposed in parallel with the differential lock switch 40 in the electric circuit of the magnetic valve 36 for operating the differential lock mechanism 35 of the third differential 7 (see FIG. 1). The relay 52 is a differential lock mechanism 3
When the indicator lamp switch 51 is turned on, the battery is turned on by the battery current that turns on the indicator lamp 50 (the contact is closed by the excitation of the solenoid).
Then, the battery current bypassing the differential lock switch 40 is supplied to the solenoid of the magnetic valve 36. FIG.
, The same reference numerals are given to the same components as those in FIG.

With this configuration, when the parking brake is operated, the pressure in the spring brake chamber 30a (holding the spring brake in a non-operating state) is discharged from the hand control valve 32a, and when the indicator lamp switch 51 is turned on, The current supplied from the battery 42 turns on the ignition lamp 50 and operates the relay 52. By the operation of the relay 52, the energization of the solenoid of the magnetic valve 36 is turned on, and the pressure from the tank 37 is supplied to the actuator 35a. Therefore, the differential lock mechanism 35 of the third differential device 7 is operated (the sliding clutch 21 is operated). Shift to the differential lock position). Since the third differential device 7 is maintained in the differential lock state (direct connection between the rear front shaft and the rear rear shaft) in the operating state of the parking brake, the wheels of the rear front shaft 2 are the same as in the case of FIG. The spring brakes acting on the wheels 2a and 2b can be transmitted from the wheels 3a and 3b of the rear rear shaft 3 to the road surface.

In the case of FIG. 4, if the ignition switch 41 in the cab is turned off while the parking brake is operating, the operation of the differential lock mechanism 35 is released. This is prevented by a third embodiment shown in FIG. 5, in a differential lock circuit, a magnet bubble 61 for supplying and discharging the pressure of the actuator 35a in parallel with the magnetic valve 36.
Is interposed. The magnetic valve 61 has two solenoids, one of which is
An OFF contact of a relay 60, which will be described later, and the other solenoid are also wired to an ON contact. The relay 60
This is for linking the magnetic valve 61 to the hall park (parking brake). When the indicator lamp switch 51 is turned on, the indicator lamp 50 is turned on.
When energization to the solenoid 60a is turned on by a battery current that turns on, the ON contact closes via the mover, while the energization to the solenoid 60a is turned off by turning off the indicator lamp switch 51. O
The FF contact closes via the mover.

The magnetic valve 61 is switched when the power supply to one of the solenoids is turned on via the ON contact of the relay 60, and supplies the pressure from the tank 37 to the actuator 35a, while supplying the pressure via the OFF contact of the relay 60. When the power supply to the other solenoid is turned on, the operation is switched to discharge the pressure from the actuator 35a.
When the ignition switch 41 is turned off, the relay 6
When the battery current supplied via the ON contact or OFF contact of 0 is cut off, the magnetic valve 61
The two solenoids are both deactivated, and are held at the valve position at that time (when the ignition switch 41 is OFF).

Therefore, even if the ignition switch 41 is turned off in the operation state of the parking brake, the magnetic valve 61 is not switched, so that the differential lock mechanism 35 of the third differential device 7 can be maintained in the operation state. Reference numeral 62 denotes a double check valve for selectively connecting the magnetic valve 61 side and the magnetic valve 36 side to the actuator 35a. 5, the same components as those in FIG. 4 are denoted by the same reference numerals.

In the first to third embodiments, the differential lock mechanism 35 of the third differential 7 is linked to the parking spring brake, but is linked to the mechanical parking wheel brake. It may be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a third differential device.

FIG. 3 is a circuit configuration diagram according to the first embodiment.

FIG. 4 is a circuit configuration diagram according to a second embodiment.

FIG. 5 is a circuit configuration diagram according to a third embodiment.

[Explanation of symbols]

2 Rear front shaft (drive shaft) 3 Rear rear shaft (drive shaft) 7 Third differential (inter differential mechanism) 8a, 8b Wheel park (parking spring brake) 30, 30a Parking spring brake chamber 32, 32a Hand Control valve 35 Differential lock mechanism of third differential 35a Actuator of differential lock mechanism 36,61 Magnetic valve 38 Relay emergency valve 50 Indicator light of parking spring brake 51 Indicator light switch 52,60 Relay

Claims (4)

[Claims] 1. A vehicle provided with a third differential that absorbs a rotational difference between a front drive shaft and a rear drive shaft, wherein the third differential is in a differential lock state while a parking wheel brake is in an operating state. Means for interlocking the differential lock mechanism of the third differential with the parking wheel brake in order to maintain the parking brake device. 2. A vehicle equipped with a third differential that absorbs a rotational difference generated between a front drive shaft and a rear drive shaft. A parking brake device comprising: a relay emergency valve that supplies and discharges an operating pressure of a differential lock mechanism of the differential device. 3. A magnetic valve for supplying and discharging an operating pressure of a differential lock mechanism of a third differential device in a vehicle having a third differential device for absorbing a rotational difference generated between a front drive shaft and a rear drive shaft. A relay that turns on and off the power supply to the parking wheel brake according to the indicator lamp switch,
A parking brake device comprising: 4. A vehicle provided with a third differential that absorbs a rotational difference generated between a front drive shaft and a rear drive shaft, a valve is provided at a position for supplying an operating pressure of a differential lock mechanism of the third differential. A magnetic valve that has a solenoid that switches the valve to a position that discharges the operating pressure as well as a solenoid that switches, a relay that selectively turns on the power to the two solenoids of the magnetic valve according to the indicator light switch of the parking wheel brake, A parking rake device comprising: