JPH0637024Y2 - Vehicle braking system - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a braking device for agricultural vehicles such as speed sprayers and tractors, which performs a small turn using a single brake, and more specifically, left and right brake pedals. The present invention relates to a braking device that can accurately perform one-sided braking without stepping on.

[Conventional technology]

FIG. 10 is a side view of the speed sprayer 10. The speed sprayer 10 includes a frame 16 which is supported by front wheels 12 and rear wheels 14 and is capable of self-propelling. The frame 16 of the speed sprayer 10 includes a driving unit 18, which is sequentially arranged from the front.
Chemical tank 20, engine room 22, spout 24, and blower
26 are arranged. The front wheels 12 have a function as steering wheels.

11 and 12 are schematic views of a conventional braking device of the speed sprayer 10 (eg, Japanese Utility Model Laid-Open No. 55-65251) viewed from above and from the side of the speed sprayer 10. The front axle 28 and the rear axle 30 have front wheels 12 and 12 and rear wheels 14 and 14 attached to the left and right ends, respectively, and support the front and rear ends of the frame 16, respectively. In the driving unit 18, the steering wheel 32 is arranged in front of the seat 34 and is integrally and rotatably fixed to the upper end of the steering shaft 36. The gear box 38 is fixed to the frame 16,
Connected to the lower end of the steering shaft 36,
Is converted into the swing of the pitman arm 40. The drag link 42 extends in the front-rear direction of the speed sprayer 10 and is rotatably coupled to the lower end of the pitman arm 40 and the right knuckle arm 44 at the front and rear ends thereof.
The left and right knuckle arms 44 are integrally connected to the left and right front wheels 12, 12 in the turning direction, and the tie rods 45 are rotatably connected to the left and right knuckle arms 44, 44 at both left and right ends. In the driving unit 18, further, a left brake pedal 46a and a right brake pedal 46b are separately provided at the feet of the driver, and the left master cylinder 48a and the right master cylinder 48b are
A hydraulic pressure related to the depression amount of the left brake pedal 46a and the right brake pedal 46b is generated, and this hydraulic pressure is sent to the left braking mechanism 52a and the right braking mechanism 52b via the left pipe 50a and the right pipe 50b.

FIG. 13 shows the braking device on the left side. The configuration of the braking device on the right side is the same as that in FIG. 13, although not shown. The left brake pedal 46a is swingably supported around the support shaft 54, and the left piston rod 5 of the left master cylinder 48a is supported.
The 6a is rotatably connected to the lower end of the left brake pedal 46a via a left connecting arm 58a. Left oil reservoir 60
a is the left master cylinder that stores the oil and through the pipe 62a
It is connected to 48a. The left braking mechanism 52a includes a brake thinner 64 that is supplied with hydraulic pressure from the left master cylinder 48a via the left pipe 50a. Brake shoes 66,66
Is swingably supported by a common anchor pin 68 at the lower end portion, is expanded by the extension of the brake cylinder 64, engages with the drum of the left rear wheel 14 with a predetermined force, and brakes the rear wheel 14.

FIG. 14 shows the left brake pedal 46a and the right brake pedal 46b.
The connection mechanism of is shown. The connecting arm 70 is disposed on the back side of the right brake pedal 46b, the base end portion is swingably supported around a fulcrum 69, and the tip end side can project and retract to the back side of the right brake pedal 46b. . Left stopper
71a and the right stopper 71b are the left brake pedal 46 and
It is provided so as to project from the back side of the a and right brake pedals 46b and contacts the tip of the connecting arm 70 to regulate the swing range of the connecting arm 70. When the connecting arm 70 is in a position where it projects to the back side of the left brake pedal 46a and contacts the left stopper 71a,
The driver can select the left brake pedal 46a and the right brake pedal 4
When one of the 6b is depressed, the left brake pedal 46a and the right brake pedal 46b simultaneously swing. Further, when the connecting arm 70 is pulled toward the right brake pedal 46b and is in a position where it is in contact with the right stopper 71b, the left brake pedal 46a and the right brake pedal 46b swing independently.

When driving the speed sprayer 10 on the road,
The connecting arm 70 in FIG. 14 is tilted to the left stopper 71a side so that the left brake pedal 46a and the right brake pedal 46b integrally swing. Driver's right foot, left brake pedal
When one of 46a and the right brake pedal 46b is depressed, a predetermined hydraulic pressure is generated in both the left master cylinder 48a and the right master cylinder 48b, both the left braking mechanism 52a and the right braking mechanism 52b are activated, and the left and right rear wheels are activated. 14 is braked.

[Problems to be solved by the device]

The problems of such a conventional braking device are listed below.

(A) The connecting arm 70 is tilted to the left brake pedal 46a side and the right brake pedal 46b side to operate the left braking mechanism 52a and the right braking mechanism 52b simultaneously and independently. Connecting arm for traveling inside
The operation of switching the position of 70 is complicated, and the switching operation may be forgotten.

(B) The driver needs to correctly select and depress the brake pedal on the inner side in the turning direction in order to use one brake, but the selection is complicated and there is a risk of accidentally depressing the reverse brake pedal. There is. If the wrong brake pedal is depressed, an excessive force acts on the steering mechanism and the drive system, possibly causing damage.

(C) Since it is necessary to dispose two brake pedals at the relatively narrow feet of the driving unit 18, this is a problem in terms of securing space and downsizing the speed sprayer 10. Further, since the driver sometimes wears boots or the like, his / her feet are further narrowed due to the two brake pedals.

An object of the present invention is to provide a braking device for a vehicle that overcomes the above-mentioned problems by appropriately operating one and both brakes with one brake pedal.

[Means for Solving the Problems]

The invention will be described using the reference numerals of the drawings corresponding to the embodiments.

A braking device for a vehicle (10) according to claim 1, wherein a brake pedal (72) operated by a driver and a brake pedal hydraulic cylinder (74, 74) for generating a hydraulic pressure related to an operation amount of the brake pedal (72). 74a, 74b), a left braking mechanism (52a) and a right braking mechanism (52b) which are provided corresponding to the left and right rear wheels (14) and brake each rear wheel (14), and the steering wheel (32). When the amount of rotation to the left and right is less than the specified value, it is applied to both the left braking mechanism (52a) and the right braking mechanism (52b), and when the amount of rotation is greater than the specified value, the left braking mechanism (52a) or the right braking mechanism that corresponds to the rotation direction. The mechanism (52b) includes a first brake switching valve (82) for communicating the brake pedal hydraulic cylinders (74, 74a, 74b).

In the braking device for a vehicle (10) according to claim 2, the second brake switching valve (78) bypasses the first brake switching valve (82) to bypass the left braking mechanism (52a) and the right braking mechanism (52b). The position where the brake pedal hydraulic cylinders (74, 74a, 74b) are connected to both, and the brake pedal hydraulic cylinders (74, 74a, 74b)
Is connected to the first brake switching valve (82) and is switched by the manual lever (80).

In the braking device for a vehicle (10) according to claim 3, the cam (84) includes:
Three peripheral parts with different distances from the center of rotation (90,92,9
4) is provided and rotates in relation to the rotation of the steering wheel (32). The first brake switching valve (82) is connected to the cam (8
The switching position is controlled by the rotational displacement of 4).

[Action]

In the invention of claim 1, when the vehicle (10) is driven on a road or the like, a sharp turn is not required, and the amount of left / right rotation of the steering wheel (32) is less than a predetermined value. Therefore, the hydraulic pressure generated in the brake pedal hydraulic cylinders (74, 74a, 74b) along with the depression of the brake pedal (72) is switched by the first brake switching valve (82), and the left braking mechanism (52a). And right braking mechanism (52
sent to both b). As a result, the left and right rear wheels (14) are braked and both brakes can be obtained.

When the vehicle (10) is traveling in a field or the like, a small turn is required, so the steering wheel (32) is rotated largely to the left or right, and the steering wheel (32) is rotated.
The amount of rotation to the left or right of is greater than or equal to a predetermined value. Therefore, the hydraulic pressure generated in the brake pedal hydraulic cylinders (74, 74a, 74b) when the brake pedal (72) is depressed is
The brake switching valve (82) is selectively switched to the left braking mechanism (52a) or the right braking mechanism (52b) on the inner side in the turning direction of the vehicle (10). As a result, the left or right rear wheel (14) is braked and a one-sided brake can be obtained.

In the invention of claim 2, the second brake switching valve (78) is
The position is switched by the manual lever (80), and at a predetermined position, the hydraulic pressure of the brake pedal hydraulic cylinders (74, 74a, 74b) does not pass through the first brake switching valve (82) and the left braking mechanism (52a). And directly to both the right braking mechanism (52b).
In this state, both brakes can be obtained regardless of the amount of rotation of the steering wheel (32).

In the invention of claim 3, the cam (84) rotates in association with the rotation of the steering wheel (32). The three peripheral portions (90, 92, 94) of the cam (84) are involved in the switching position of the first brake switching valve (82) and are related to the rotation amount of the steering wheel (32) (90, 92, 94). 92, 94) determines the switching position of the first brake switching valve (82), and the left or right single brake,
And both brakes are obtained.

〔Example〕

The invention will be described below with reference to the embodiments shown in FIGS. The parts already described in FIG. 10 and subsequent figures are designated by the same reference numerals and the description thereof will be omitted.

3 and 4 are schematic views of the braking device of the speed sprayer 10 from above and from the side thereof. One brake pedal 72 is arranged at the foot of the driver 18 and is operated by the driver's right foot. The left master cylinder 74a and the right master cylinder 74b are brake pedals.
It is operated by 72 and is connected to the second brake switching valve 78 via the left pipe 76a and the right pipe 76b, respectively, and the second brake switching valve 78 is manually operated in the switching position by the manual lever 80. The switching position of the first brake switching valve 82 is operated by the cam 84, the inlet side is connected to the outlet side of the second brake switching valve 78 via the left pipe 86a and the right pipe 86b, and the left pipe 50a is connected. The outlet side is connected to the left braking mechanism 52a and the right braking mechanism 52b via the right pipe 50b. The left bypass pipe 87a and the right bypass pipe 87b are the first brake switching valve.
Bypassing 82, the outlet side of the second brake switching valve 78 is directly connected to the left pipe 50a and the right pipe 50b.

FIG. 5 is a configuration diagram of the swinging portion of the brake pedal 72. The brake pedal 72 is swingable around the support shaft 54, and the left connecting arm 58a and the right connecting arm 58b are rotatably connected to the lower end portion of the common brake pedal 72.

FIG. 6 is a configuration diagram of a part of the left braking device in the vicinity of the brake pedal 72. Although illustration is omitted,
The configuration of the corresponding portion of the right braking device is also the same as in FIG. The left connecting arm 58a is rotatably connected at both ends thereof to the left piston rod 56a of the left master cylinder lid 74a and the lower end of the brake pedal 72, thus
With the depression operation of 72, the left piston rod 56a is axially displaced, and a hydraulic pressure related to the depression amount of the brake pedal 72 is generated in the left master cylinder 74a.

7 and 8 are views of the vicinity of the gear box 38 in the steering mechanism as viewed from the side and from above. The cam 84 is fitted on the output shaft 88 of the gear box 38 together with the upper end of the pitman arm 40, and is a nut screwed to the output shaft 88.
It is tightened by 89 and rotates integrally with the output shaft 88.

FIG. 9 is a configuration diagram showing a connection relationship between the second brake switching valve 78 and the cam 84. Circumferential part 90 for left turn, peripheral part for neutral
92 and the right turning peripheral portion 94 are formed on the peripheral portion of the cam 84,
The distance from the rotation center of the cam 84 is gradually increased stepwise. The roller 96 is rotatably supported by the tip of the operating rod 98 of the second brake switching valve 78, and the pressing state of the cam 84 against the peripheral portion is maintained. Operation rod 98 in relation to the rotational position of the cam 84
The axial position of is changed, and the first brake switching valve 82 is switched. For example, the maximum left / right steering angle of the front wheels 12 is 45 °.
Then, the neutral peripheral portion 92 is set so as to correspond to a steering angle range of less than 40 °, and the left turning peripheral portion 90 and the right turning peripheral portion 94 have a left and right steering angle range of 40 ° or more. Set to correspond to.

FIG. 1 is a hydraulic circuit diagram showing the connection relationship between the second brake switching valve 78 and the first brake switching valve 82, and the left braking mechanism 52a and the right braking mechanism 52b. The second brake switching valve 78 is
The switching position is operated by the manual lever 80 to selectively connect the left pipe 76a and the right pipe 76b to the left pipe 86a and the right pipe 86b or to the left bypass pipe 87a and the right bypass pipe 87b.
The first brake switching valve 82 includes a left pipe 86a and a right pipe 86b.
The left pipe 50a at the switching position on the left side in FIG.
To the right pipe 50b only in the right switching position and to both the left pipe 50a and the right pipe 50b respectively in the central neutral position.

The operation of the embodiment will be described.

The second brake switching valve 78 is normally the left master cylinder
74a and the right master cylinder 74b to the first brake switching valve 82
The switch is set to connect to.

When driving the speed sprayer 10 on a road,
Since the turning amount of the steering wheel 32 to the left and right is less than a predetermined value (corresponding to a steering angle of less than 40 ° in the example shown in the figure) without requiring a sharp turn, the neutral circumference of the cam 84 is reduced. The part 92 contacts the roller 96 at the tip of the operating rod 98 of the second brake switching valve 78, and the first brake switching valve
82 is in the neutral position of FIG. Therefore, the hydraulic pressure generated in the left master cylinder 74a and the right master cylinder 74b due to the depression of the brake pedal 72 is switched by the first brake switching valve 82 and sent to both the left braking mechanism 52a and the right braking mechanism 52b. To be As a result, the left and right rear wheels 14 are braked and both brakes can be obtained.

When traveling the speed sprayer 10 in a field,
Since a small turning is required, the steering wheel 32 is largely rotated left or right, and the steering wheel 32
The amount of left / right rotation of the
(Corresponding to more than 0 °), the left turn peripheral portion 90 or the neutral peripheral portion 92 of the cam 84 comes into contact with the roller 96 at the tip of the operating rod 98 of the second brake switching valve 78, and the first brake is applied. The switching valve 82 is at the left switching position or the right switching position in FIG. Therefore, the hydraulic pressure generated in the left master cylinder 74a and the right master cylinder 74b with the depression of the brake pedal 72 is switched by the first brake switching valve 82, and the left braking mechanism on the inner side in the turning direction of the speed sprayer 10 is operated. It is sent only to 52a or only to the right braking mechanism 52b.
As a result, the left or right rear wheel 14 is braked and a one-sided brake can be obtained.

The manual lever 80 is operated to bring the second brake switching valve 78 to the switching position where the left pipe 76a and the right pipe 76b are connected to the left bypass pipe 87a and the right bypass pipe 87b, respectively. As a result, the hydraulic pressures of the left master cylinder 74a and the right master cylinder 74b do not pass through the first brake switching valve 82 and the left braking mechanism 52a.
And to the right braking mechanism 52b directly. In this state, both brakes are obtained regardless of the amount of rotation of the steering wheel 32, and when the speed sprayer 10 is traveling on a general road, even if the steering wheel 32 is rotated to the maximum extent, it will be one-sided brake. You can avoid that.

FIG. 2 is a hydraulic circuit diagram when the left master cylinder 74a and the right master cylinder 74b in FIG. 1 are combined into one master cylinder 74. The second brake switching valve 78 is connected to the pipe 76.
To the first brake switching valve 82, and the piping
A switching position connecting 76 to both the left bypass pipe 87a and the right bypass pipe 87b. First brake switching valve 82
Is the pipe 86, and the left pipe 50a in the switching position on the left side of FIG.
To the right pipe 50b at the left switching position, and to both the left pipe 50a and the right pipe 50b at the central neutral position.

[Effect of device]

According to the first aspect of the invention, the first brake switching valve automatically controls the connection between the brake pedal hydraulic cylinder and the left braking mechanism and the right braking mechanism in relation to the rotation amount of the steering wheel. It is possible to simplify the brake operation without having to make a single judgment as to which one of the left brake mechanism and the right brake mechanism should be operated in order to operate the single brake, the both brakes, and the single brake. It is possible to obtain a proper brake operation. Further, unlike the conventional case, the trouble of switching the connecting arm 70 (FIG. 14) one by one according to the traveling condition can be omitted.

Further, since only one brake pedal is required at the foot of the driving unit, the space for the brake pedal can be reduced and the foot space can be expanded.

According to the second aspect of the present invention, the second brake switching valve which is switched by the manual lever is provided, and the hydraulic pressure of the brake pedal hydraulic cylinder is set to the first brake switching valve at the predetermined switching position of the second brake switching valve. It can be sent directly to both the left braking mechanism and the right braking mechanism without going through. As a result, both brakes can be reliably obtained regardless of the amount of rotation of the steering wheel, and the possibility of one-side braking occurring during traveling on the road can be eliminated.

According to the third aspect of the present invention, the first brake switching valve can be switched and operated by the rotation of the cam that is interlocked with the rotation of the steering wheel, and the electric circuit for switching and operating the first brake switching valve is complicated. Does not require expensive equipment,
It can be simplified.

[Brief description of drawings]

1 to 9 relate to an embodiment of the present invention, and FIG. 1 is a hydraulic circuit diagram showing a second brake switching valve and a connection relationship between the first brake switching valve and a left braking mechanism and a right braking mechanism, FIG. 2 is a hydraulic circuit diagram in which the left master cylinder and the right master cylinder of FIG. 1 are combined into one master cylinder, and FIGS. 3 and 4 show an outline of the braking device of the speed sprayer above the speed sprayer. And FIG. 5 is a side view, FIG. 5 is a block diagram of the swing portion of the brake pedal, FIG. 6 is a block diagram of the left braking device in the vicinity of the brake pedal, and FIGS. The figure which looked at the range near the gearbox in a mechanism from the side and above, FIG. 9 is a block diagram which shows the connection relation of a 2nd brake switching valve and a cam, and FIG. 10 is a side view of a speed sprayer.
11 to 14 relate to the prior art, and FIGS.
The figure shows an outline of a conventional braking device of a speed sprayer from above and sideways of the speed sprayer, FIG. 13 shows a left braking device, and FIG. 14 shows a connecting mechanism of a left brake pedal and a right brake pedal. FIG. 10 …… Speed sprayer (vehicle), 14 …… Rear wheel, 32…
… Steering wheel, 52a …… Left braking mechanism, 52b ……
Right braking mechanism, 72 ... Brake pedal, 74 ... Master cylinder (hydraulic cylinder for brake pedal), 74a ... Left master cylinder (hydraulic cylinder for brake pedal), 74b
...... Right master cylinder (hydraulic cylinder for brake pedal), 78 …… Second brake switching valve, 80 …… Manual lever, 82 …… First brake switching valve, 82 …… Cam, 90 ……
Left turn peripheral part (circumferential part), 92 …… Neutral peripheral part (circumferential part), 94 …… Right turn peripheral part (circumferential part).

Claims (3)

[Scope of utility model registration request] 1. A brake pedal (72) operated by a driver, and a brake pedal hydraulic cylinder (74, 7) for generating a hydraulic pressure related to an operation amount of the brake pedal (72).
4a, 74b), a left braking mechanism (52a) and a right braking mechanism (52b) which are provided corresponding to the left and right rear wheels (14) and brake each rear wheel (14), and the steering wheel (32). If the amount of rotation to the left and right is less than the specified value, the left braking mechanism
a) and the right braking mechanism (52b), and the left braking mechanism (52a) corresponding to the direction of rotation when the value exceeds a predetermined value.
Alternatively, a vehicle braking device comprising a first brake switching valve (82) for communicating the brake pedal hydraulic cylinders (74, 74a, 74b) with the right braking mechanism (52b). 2. A second brake switching valve (78) is provided with the first brake switching valve (78).
By bypassing the brake switching valve (82) of the left brake mechanism (52
a) and a position where the hydraulic cylinder (74, 74a, 74b) for the brake pedal is connected to both the right braking mechanism (52b),
The hydraulic cylinder (74, 74a, 74b) for the brake pedal has a position for connecting to the first brake switching valve (82), and can be switched by a manual lever (80). Vehicle braking system. 3. A cam (84) is provided with three peripheral portions (90, 92, 94) having different distances from the center of rotation, and the cam (84) rotates in relation to the rotation of the steering wheel (32), The braking device for a vehicle according to claim 1 or 2, wherein a switching position of the first brake switching valve (82) is controlled by a rotational displacement of the cam (84).