JPH07232623A - Running brake of tractor - Google Patents

Abstract

PURPOSE:To classify right and left brakes into individual right or left brake and simultaneous right and left brake by changing over respective solenoid valves for one-sided brake and both brakes, even at individually stepping down right and left brake pedals. CONSTITUTION:This running brake of a tractor is provided with a solenoid valve 4 for both brakes simultaneously braking right and left brakes 1R,1L, and a slolenoid valve 5 for one-sided brake braking one-sided brake 1R or 1L, on the oil pressure circuit 3 of brake cylinders 2R, 2L which receive oil pressure from an oil pressure pump P and can operate individually the right and left brakes 1R, 1L, and a relief valve 7 is provided in a relief circuit 6 connecting extending over between both brake cylinders 2R, 2L.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling brake for a tractor, and can be used for a brake device for braking left and right brakes respectively by hydraulically operated left and right brake cylinders.

[0002]

2. Description of the Related Art Conventionally, as a traveling brake of a tractor, it is general that a brake is directly braked by a foot-operated brake pedal via a brake rod and an arm. When the left and right brake pedals are separately depressed, the brakes on only one side are braked respectively, and when the left and right brakes are simultaneously depressed, both brakes are simultaneously braked. When traveling at high speed, the left and right brake pedals are connected by an appropriate connecting tool.

However, when the left and right traveling brakes are selectively used for braking on one side only and braking on both sides simultaneously, it is necessary for an operator to selectively operate the brake pedal on one side and on both sides. It is very troublesome to use them properly, and an incorrect operation may occur when the position of the foot is bad. For this reason, there is a means for switching the brake pedal to the connected state or the non-connected state, but this switching operation is very troublesome, and there is a risk of accidents if this connection is inadvertently forgotten when driving at high speed.

When both brakes are braked at the same time, if the play adjustments of the left and right brakes are not uniform, the braking strengths of both brakes become uneven, increasing the risk. Therefore, according to the present invention, even when the left and right brake pedals are separately depressed, the left and right brakes are separately braked by switching the solenoid valves for one brake and both brakes. And left and right simultaneous braking.

[0005]

The present invention receives the hydraulic pressure from a hydraulic pump P and also brakes 1L and 1R on the left and right.
The hydraulic circuit 3 of the brake cylinders 2L and 2R capable of individually braking each of the above, the solenoid valve 4 for both brakes for simultaneously braking the left and right brakes 1L and 1R, and the brake 1L on one side.
Or solenoid valve 5 for one-sided brake that brakes only 1R
Is provided, and a relief valve 6 is provided in a relief circuit 6 connected between both brake cylinders 2L and 2R to provide a traveling brake for a tractor.

[0006]

When the both brake solenoid valves 4 are switched to one side, the left and right brakes 1L and 1R are actuated by the operation of the left and right brake cylinders 2L and 2R.
Brake at the same time. Further, when the valve 4 is switched to the other side, the valve 5 is connected to the one-brake solenoid valve 5 to switch the valve 5 to one side, so that, for example, only the left brake 1L is operated by operating the left brake cylinder 2L. By braking and switching the valve 5 to the other side, for example, only the right brake 1R is braked by the operation of the right brake cylinder 2R. By connecting the relief valve 7 between both brake cylinders 2L and 2R, the pressure in both cylinders 2L and 2R can be held uniformly.

As described above, by the simple operation of switching the solenoid valves 4 for both brakes and the solenoid valve 5 for one brake, the left and right brakes 1L, 1L,
Since one-brake braking in which the 1R is braked on only one side and both-brake braking in which both sides are simultaneously braked can be performed, there is almost no troublesome operation for switching the brake 1 between connected and unconnected, and an erroneous operation can be prevented. Prevention of occurrence and remote control by using the solenoid valves 4 and 5 and the brake cylinder 2 are possible, and there is no need to worry about securing a space for disposing the operation connecting member and the like.

Further, since the relief valve 7 connected between the brake cylinders 2L and 2R can automatically adjust and equalize the difference in hydraulic pressure between the cylinders 2L and 2R, the play adjustment of the brake 1 is unnecessary. Therefore, the braking force of both brakes 1L and 1R can be kept constant.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. An engine 9 is mounted on a front portion of a vehicle body 8 of a tractor embodying the present invention, and a transmission case 10 in which a gear change interlocking mechanism is installed from the engine 9 toward the rear.
So that power can be transmitted from the mission case 10 to the left and right front wheels 11 positioned on the front side of the vehicle body 8 and the left and right rear wheels 12 positioned on the rear side. Configure the transmission.

A bonnet 13 for covering the engine 9 is mounted on a vehicle body 8, and a steering cabin 1 for enclosing a cockpit for steering a tractor from the rear end of the bonnet 13 toward the rear.
4 are arranged in series, and the rear wheels 1 are provided on the left and right sides of the rear portion of the cabin 14.
The left and right fenders 15 that cover 2 are provided. Inside the cabin 14, a steering handle 16 and a column 17 are arranged in the front part, and the steering wheel 16 is configured to be steerable by the handle 16, and a steering seat 18 is arranged behind the handle 16, Left and right foot-operated brake pedals 20 are provided on a floor 19 provided under
L and 20R are separately arranged adjacent to each other.

A pair of left and right lower links 21 for mounting a working machine are connected to the lower rear end of the mission case 10 so as to be vertically rotatable toward the rear, and the middle position of the lower link 21 in the longitudinal direction and the mission. The front and rear ends of a pair of left and right lift arms 22 that are vertically rotated by hydraulic pressure extending rearward from the upper side surface of the rear end of the case 10 are connected by expandable left and right adjustment links 23, respectively, and the mission A PTO shaft 24 for driving the working machine is provided to project rearward from the rear end surface of the case 10.

The left and right brakes 1L and 1R provided in the transmission interlocking mechanism path of the mission case 10 are provided with one end of the left and right brake arms 25 for braking the brake 1, and the other end of the brake arm 25 is attached. In addition, the left and right brake cylinders 2L that expand and contract due to hydraulic pressure,
Pistons 2La and 2Ra of 2R are rotatably connected to each other, and the left and right brakes 1L and 1R are braked separately or at the same time by operating the left and right brake cylinders 2L and 2R.

The hydraulic circuit 3 for actuating the left and right brake cylinders 2L, 2R has a hydraulic pump P as shown in FIG.
A brake solenoid valve 4 for switching the pressure oil discharged from the brake cylinder 2L, 2R to the simultaneous operating side W of both brake cylinders 2L and the operating side S of only one side is provided, and this both brake solenoid valve 4 is connected to both brake cylinders 2L. , 2R
When switched to the simultaneous operation side W of (1), pressure oil flows to both brake cylinders 2L and 2R via the check valves 26, respectively, and both brake cylinders 2L and 2R are connected so as to operate simultaneously. Further, when the solenoid valves 4 for both brakes are switched to the operating side S of only the left and right brake cylinders 2L or 2R, connection is made so that pressure oil flows from the solenoid valves 4 for both brakes to the solenoid valve 5 for one brake, Further, the one-side brake solenoid valve 5 is provided with the left side brake cylinder 2L side SL from the neutral position N
When switched to, the pressure oil flows to the left brake cylinder 2L, and the one-brake solenoid valve 5 is moved to the neutral position N.
When the switch is made to the right brake cylinder 2R side SR, pressure oil flows to the right brake cylinder 2R, and the left and right brake cylinders 2L or 2R are connected so as to be operated separately.

The relief circuit 6 is also shown in FIG.
As shown in FIG. 5, the relief valve 7 is connected to the merging portion which is connected from both brake cylinders 2L and 2R via the check valve 27, and the hydraulic pressure of both brake cylinders 2L and 2R is automatically adjusted by the action of this relief valve 7. The braking force of the left and right brakes 1L and 1R is adjusted so as to prevent one-sided effect. Separately from this relief valve, left and right orifices 28 for flow rate adjustment are respectively connected between both brake cylinders 2L and 2R and each check valve 27.

An electric circuit 2 for switching between the solenoid valves 4 for both brakes and the solenoid valve 5 for one brake.
9 is the left brake pedal 20L, as shown in FIG.
Left pedal switch 30a that turns on when you depress
ON when the right brake pedal 20R is depressed
The right pedal switch 30b is engaged with the left and right brake pedals 20L and 20R.
Output side terminals F of the left and right pedal switches 30a and 30b
And a double changeover switch 3 for switching between the solenoid valve 4 for both brakes and the solenoid valve 5 for one-side braking.
1 and the input side both terminals C are connected respectively, and the output side both terminals W of the changeover switch 31 are connected to the solenoid coil terminals of both the brake solenoid valves 4 by a common line, and the output side terminals S (L ) And S (R) to the respective solenoid coil terminals of the one-brake solenoid valve 5. The changeover switch 31 is the column 1
It is provided at an appropriate position of 7.

The hydraulic circuits 3 and 6 and the electric circuit 29
By the action, when the operator switches the changeover switch 31 to the S side at the time of work etc., both brake solenoid valves 4 are turned off and are located on the S side.
At this time, when the left brake pedal 20L is depressed, the solenoid valve 5 for one-sided brake is switched to the SL side, the left brake cylinder 2L is operated and the left brake arm 25 brakes the left brake 1L, and the right brake pedal 20R. By depressing, the right brake 1R is braked by the same operation. Further, when the changeover switch 31 is switched to the W side during high speed traveling, the both brake solenoid valves 4 are turned on and switched to the W side, and both brake cylinders 20L and 20R are depressed regardless of whether the both brake cylinders are depressed. 2L and 2R are operated at the same time to connect both brakes 1L and 1R to brake at the same time. like this,
Switching between the connection and disconnection of the two brakes 1L and 1R can be easily and easily performed only by operating the changeover switch 31, without the conventional means for mechanically connecting the brake pedal 20. It is possible to prevent an erroneous operation due to a wrong position.

By the action of the relief valve 7, the hydraulic pressures of both brake cylinders 2L and 2R can be automatically equalized, and the play of the brake 1 need not be adjusted. Therefore, the braking force of both brakes 1L and 1R can be reduced. It can be held constant. As shown in FIG. 8, the hydraulic circuit 3 shown in FIG. 2 has a circuit configuration in which an opening / closing valve is used as the solenoid valves 4 for both brakes, and a direction switching valve is used as the solenoid valve 5 for one-sided brakes. Can be simplified. As described above, the hydraulic circuit 3 has various circuit configurations, but any other circuit configuration may be used without departing from the gist of the present invention.

A depression angle sensor 32 for detecting the depression angle (amount) of the brake pedal 20 is arranged at a position where it can engage with the left and right brake pedals 20L and 20R, respectively, as shown in FIG. As shown in FIG. 5, the both brake solenoid valves 4 are connected to the depression angle sensor 32.
By using a proportional solenoid valve that controls the hydraulic pressure of the brake cylinder 2 in proportion to the depression angle detected by the brake switch 2, the changeover switch 31 is switched to the simultaneous operation side W of both brake cylinders 2L and 2R.
When L and 1R are connected, the shock during braking can be reduced, and at the same time, it can be used in a half-brake state. When the changeover switch 31 is switched to the left and right separately operating side S of both brake cylinders 2L and 2R and each brake is individually braked by the one brake 1L or 1R,
Since there are few cases where delicate braking is required, even if a normal valve is used as the one-brake solenoid valve 5, there is no problem and the cost can be reduced.

The depression angle sensor 32 detects the depression angle of the left brake pedal 20L or the right brake pedal 20R, and is provided in the transmission interlocking mechanism path of the mission case 10 as shown in the flowchart of FIG. When the high speed side H is detected by the high speed sensor 33 for detecting the high / low switching of the sub speed change in the sub speed change for switching the vehicle speed between high and low, the left and right brakes are controlled by the arithmetic control of the controller 34 shown in FIG. Pedal 20
Regardless of whether L or 20R is depressed, both brake solenoid valves 4 are operated to brake both brakes 1L and 1R at the same time, and when the high speed sensor 33 does not detect the high speed side H, the one brake solenoid valve 5 is operated. Then, when the left brake pedal 20L is depressed, the left brake 1L is braked separately, and when the right brake pedal 20R is depressed, the right brake 1R is individually braked. By these actions, it is possible to prevent a risk of falling due to one-side braking at high speed due to forgetting to connect the brake pedal 20.

In addition to preventing the vehicle from tipping over at high speeds, when the vehicle body 8 leans forward or backward or left or right even at low speeds when the high speed sensor 33 does not detect it, as shown in FIG. When the value detected by the front-rear inclination sensor 35 or the left-right inclination sensor 36 that detects the inclination or the left-right inclination reaches a constant value (set angle) set in the controller 34, first, the alarm 37 provided in the vehicle body 8 is activated. When the vehicle is tilted beyond this constant value, as shown in FIG. 7, the changeover switch 31 automatically switches the brakes 1L and 1R simultaneously so that both brake pedals 20L and 20R are depressed at the same time. A control means is provided for keeping the connection state. As a result, when the vehicle body 8 leans over a certain value, such as when crossing a ridge, it is possible to prevent one-side brake braking to prevent the vehicle from overturning, and also to let the operator recognize these dangerous lean areas in advance by operating the alarm 37. You can

Further, as shown in FIG. 9, the changeover switch 3 is provided at a portion (dashed line) corresponding to the electric circuit of FIG.
Instead of 1, various data (eg sharp turn, ridge crossing,
A brake reset switch 38 (Datatronic) for turning off the switch by an input such as high speed running is provided, and each brake of the one brake 1L or 1R and both brakes 1L, 1
Simultaneous braking of R does not depend on manual operation by the operator, but the reset switch 38
Is turned OFF and the solenoid valves 4 for both brakes are automatically switched to the simultaneous braking side, thereby preventing forgetting to connect the both brakes 1L, 1R in a dangerous state.
The switch is turned off by inputting data such as high-speed running.
PTO reset switch 40 (Datatronic)
The reset switch 40 is turned off by a data input, and the open / close solenoid valve 39 for turning on / off the PTO clutch is automatically turned off to stop the driving of the working machine. By interlocking the brake reset switch 38 and the PTO reset switch 40 in this manner,
By connecting both brakes 1L and 1R and stopping the driving of the PTO during high-speed traveling, it is possible to prevent the risk of falls or the like and to sufficiently improve safety.

Further, as shown in FIG. 10, the left and right brake pedals 20L and 20R are connected to each other by connecting means as shown by imaginary lines in the past, or a switch that operates at a set traveling speed. Some have automatic connection means, but these require manual operation by the operator in the former case, and there is a problem in setting the traveling speed in the latter case. For this reason,
By turning on the PTO switch 41 that is turned on only when the PTO clutch is disengaged, for example, one brake pedal 20
The electromagnet 42 fixed to L is turned on, the connecting piece 43 provided on one brake pedal 20R is pulled by sliding, and both brake pedals 20L and 20R are connected.
When the electromagnet 42 is turned off, the connecting piece 43 causes the repulsion spring 44 to move.
Since the brakes are separated from each other, it is possible to automatically switch between one-brake braking at the time of working by engaging the PTO clutch and simultaneous braking of both brakes at high-speed traveling, so both brake pedals 20L, 2L at high-speed traveling
It is possible to prevent falling without forgetting to connect 0R.

Further, as an embodiment different from the above, as shown in FIG. 11, the tip of the pitman arm 45, which swings by the steering operation of the steering handle 16, is
Stoppers 46, which come into contact when the handle 16 is fully cut, are fixed at symmetrical positions on both sides of the pitman arm 45. The stopper 46, which is conventionally fixed, is elastically urged by a buffer spring 46a. The push pins 46b are provided, and the limit switches 47 that are turned on by the push action of the push pins 46b are provided so as to be engaged with each other. By depressing a single brake pedal 20,
The left and right brake arms 25 are actuated simultaneously via the balance operating rod 48 for uniformly braking the left and right brakes 1L, 1R and the left and right brake cylinders 2L, 2R.
Both of the brake cylinders 2L and 2R are configured so that the left and right switching solenoid valves 49 which are switched by the ON operation of the limit switch 47 can be operated separately for the left and right sides.
This left / right switching solenoid valve 49 is automatically turned off by the action of the one-brake prohibiting switch 50 when the high speed sensor 33 detects the high speed side H of the auxiliary shift.
The left and right break arms 25 are simultaneously operated by the single break pedal 20.

With such a structure, the handle 16
When the steering wheel 16 is fully cut to the left, the pitman arm 45 contacts the left stopper 46, and when the handle 16 is further turned to the left from this state, the push pin 46 of the stopper 46 causes the buffer spring 46 to turn on the left limit switch 47, and switch the left / right switching solenoid valve 49 to the left to move the left brake cylinder 2
Pour pressure oil to L to brake the left brake 1L. In this way, when the steering wheel 16 is fully turned to the left or right, the brakes on the cutting side are operated separately and the steering wheel 1 is operated.
Although synchronized with six operations, when the auxiliary shift is switched to the high speed side H during this operation, one-brake braking is prohibited by this detection to prevent falling. Because of this, normally
Both brakes 1 with a single brake pedal 20 at low speed
It is possible to perform a safe driving in which L and 1R are simultaneously braked, and to separately brake each of the one-side brakes 1L or 1R on the turning side only when the steering wheel 16 is fully turned, so that the turning or the like can be smoothly performed. It is possible to simplify the pedal 20 as a single unit to reduce the cost and facilitate the stepping operation.

Further, as shown in FIG. 12, the ON / O is turned on by the lifting action of the lift arm 22 for lifting the working machine.
The steering wheel 16 is fixed by fixing the other end of the switch arm 52 by a leaf spring or the like having the FF brake switch 51 attached to one end thereof to the side wall of the mission case 10 near the lift arm 22 so that the angle can be adjusted. When the limit switch 47 is fully closed, the working machine is raised by turning on the limit switch 47, and the lift arm 22 turns on the brake switch 51 by raising the working machine.
When turned ON, a sharp turn is made by one-side brake braking on the steering wheel 16 side. In this way, by adjusting the angle of the switch arm 52 so that the brake switch 51 is turned on when the work implement is separated from the soil surface, a sharp turn can be performed before the work implement is still separated from the soil surface. It is possible to reduce the rough surface of the soil and the unpleasant shock given to the operator.

[Brief description of drawings]

FIG. 1 is a side view showing an entire tractor.

FIG. 2 is a block diagram showing a hydraulic circuit of a brake device.

FIG. 3 is a block diagram showing an electric circuit of a brake device.

FIG. 4 is a side view showing a depression angle sensor that engages with a brake pedal.

FIG. 5 is a diagram showing a relationship between a depression angle of a brake pedal and a flow rate of a solenoid valve.

FIG. 6 is a flowchart showing a braking procedure of the brake device.

FIG. 7 is a block diagram showing a control circuit of the brake device.

FIG. 8 is a block diagram showing another hydraulic circuit that replaces FIG. 2.

9 is a block diagram showing another electric circuit that replaces FIG. 3. FIG.

FIG. 10 is a plan view showing a brake pedal connecting mechanism.

FIG. 11 shows another embodiment of the brake device.

FIG. 12 is a side view showing a brake interlocking mechanism related to lifting and lowering of the working machine.

[Explanation of symbols]

 1 L. Left brake 1R. Right brake 2L. Left brake cylinder 2R. Right brake cylinder 3. Hydraulic circuit 4. Solenoid valve for both brakes 5. Solenoid valve for one-sided brake 6. Relief circuit 7. Relief valve P. Hydraulic pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koji Koyama, No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture, Engineering Department, Iseki Agricultural Machinery Co., Ltd. (72) Noriyuki Yamakawa No. 1 Yakura, Tobe-machi, Iyo-gun, Ehime Prefecture In-house (72) Inventor Shinji Otake 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture

Claims (1)

[Claims] 1. A hydraulic circuit 3 of brake cylinders 2L, 2R which receives hydraulic pressure from a hydraulic pump P and can brake the left and right brakes 1L, 1R separately.
A solenoid valve 4 for both brakes that simultaneously brakes L and 1R and a solenoid valve 5 for one brake that brakes only one side brake 1L or 1R are provided, and a relief circuit 6 is connected between both brake cylinders 2L and 2R. Is a traveling brake for a tractor provided with a relief valve 7.