JPS61215172A - Brake device for tracked vehicle - Google Patents

Abstract

PURPOSE:To operate an engine brake and a normal brake with a pedal by previously storing the relationship between the brake pedal position at engine braking and the engine target rotating speed and controlling the actual engine rotating speed to the target rotating speed. CONSTITUTION:An engine brake setter 21 outputs an engine target rotating speed signal ne against the brake pedal position signal (a) stored previously. A speed deviation detector 22 outputs a deviation signal DELTAne based on this signal and a signal NE from an engine rotating speed detector 12, a polarizing circuit 23 outputs a polarized deviation signal DELTAneo based on this signal and the speed step selection control signal A of a speed logic circuit 25, and an integrator 26 integrates this signal. Left and right adders 27, 28 add this integrated signal SIGMA and left and right output shaft steering signals SL, SR, and left and right hydraulic pump discharge control signals DL, DR are outputted to control individual actuators 7, 8. Accordingly, the rotating speed of the left and right output shafts of a stepless speed changer is controlled, and the engine rotating speed is controlled.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a brake device for tracked vehicles.

[Conventional technology]

In a hydrostatic-mechanical continuously variable speed steering system for tracked vehicles, which has two sets of left and right hydraulic pump motors and is configured to be able to perform speed change and steering at the same time, no matter what the vehicle speed, average speed ratio control is used. The engine brake force (engine brake force) can be arbitrarily selected. Conventionally, this average speed ratio control is performed based on the amount of depression of the accelerator pedal. For example, as shown in Figure 6, in a range where the amount of depression of the accelerator pedal is small, the engine brake is activated, and as the amount of depression increases , normal acceleration operations are now possible. If there is a brake pedal for normal service brakes, when attempting to fully brake the vehicle, both the engine brake using the accelerator pedal and the service brake using the brake pedal are operated at the same time or alternately. There is.

[Problem that the invention seeks to solve]

When braking a tracked vehicle equipped with a hydrostatic-mechanical continuously variable speed steering device for a tracked vehicle that is configured to have two sets of left and right hydraulic pump morphs so that shifting and steering can be performed at the same time, the above-mentioned procedure applies. However, since both the engine brake by accelerator pedal and the service brake by brake pedal are operated, the driving operation is complicated and has some problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide an entire brake system that eliminates the above-mentioned drawbacks and allows both engine braking and service braking to be performed using only the brake pedal.

[Means and effects for solving the problem] The brake device according to the present invention stores in advance the relationship between the brake pedal position and the engine target rotation speed during engine braking in the setting device, and adjusts the discharge amount of the left and right hydraulic pumps. By controlling the engine speed, the average speed ratio is increased or decreased so that the actual engine speed is always driven at this target speed, so no matter what speed the vehicle is at, the degree of engine braking can be adjusted by operating the brake pedal. It is possible to arbitrarily select only the This makes it possible to simultaneously perform two types of braking operations, normal service braking and engine braking, by operating the brake hard.
For example, it can be set in advance so that only the engine brake operates in a range where the amount of depression of the brake pedal is small, and as the amount of depression increases, the service brake starts to operate at the same time as the engine brake.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 2 is an example of a block diagram of a speed change steering device, and FIG. 1 is a block diagram of the brake device 1 in FIG.

In Figures 1 and 2, 1 is a brake device, 2 is a hydrostatic-mechanical continuously variable transmission steering device, 3 is an engine (main engine), and 4 is an input shaft of the hydrostatic-mechanical continuously variable transmission. The engine 3
5 is a left output shaft and 6 is a right output shaft. 17 is a left hydraulic pump motor, and 18 is a right hydraulic pump motor, which are elements of the hydrostatic-mechanical continuously variable speed steering system. 17a is a left hydraulic pump, 17b is a left hydraulic motor, and these two constitute the left hydraulic pump motor 17.

1, 8a is the right hydraulic pump, 18b is the right hydraulic motor,
These two constitute the right hydraulic pump motor 18.

19a is a mechanical transmission mechanism that generally includes a plurality of speed stages, 19b is a left output steering mechanism, and 19c is a right output steering mechanism. The left output shaft 5 is connected to the left output steering mechanism 19b,
Further, the right output shaft 6 is respectively connected to the right output steering mechanism 19c. The left output steering mechanism 19b and the right output steering mechanism 19c are composed of a planetary gear mechanism or the like. Reference numeral 9 denotes each speed stage selection actuator, which is connected to the mechanical transmission mechanism 19a.
, are connected to the left output steering mechanism 19b and the right output steering mechanism 19c. A left hydraulic pump discharge amount control actuator 7 is connected to the left hydraulic pump 17a. 8 is the right hydraulic pump discharge amount control actuator and the right hydraulic pop 18
connected to a. Reference numeral 10 indicates a brake pedal, and 11 indicates a dull position detector for the brake, which is provided with the brake pedal IOK.

12 is an engine rotation speed detector provided on the input shaft 4. Reference numeral 13 denotes a left output shaft rotation speed detector, which is provided on the single output shaft 5. A right output shaft rotation speed detector 14 is provided on the right output shaft 6. A left service brake 15 is provided on the left output shaft 5. A right service brake 16 is provided on the right output shaft 6. The left service brake 15 and the right service brake 16 are interlocked with the brake pedal 10 by a mechanical, hydraulic or electrical mechanism (not shown). The engine rotation speed detector 12 can be installed at a location where the rotation speed between the input shafts of either the left or right hydraulic pumps 17a, 18a can be detected from the input shaft 4, and the rotation speed can be converted into gear ratio. It can be anywhere. Similarly, if the left output shaft rotation speed detector 13 and the right output shaft rotation speed detector 14 are locations where the rotation speed of the left output shaft 5 or right output shaft 6 can be converted into a gear ratio, the left or right output shaft rotation speed detector 14 can be used, respectively. It may be installed at an appropriate location between the right hydraulic motor and the left output shaft 5 or the right output shaft 60.

The left oil pump 17a and the left hydraulic motor 17b, or the right hydraulic pump 18a and the right hydraulic motor 18b, are connected to each other by piping (not shown).

The main parts of the brake device 1 will be explained with reference to FIG. a is a brake pedal position signal output from the brake applied position detector 11, 21 is an engine brake setting device, and n8 is an engine target rotation speed signal, which is the output of the encoder brake installation device.

The brake pedal position signal a is input to the engine brake setting device 21. 22 is a speed deviation detector. N is an engine rotational speed signal and is the output of the engine rotational speed detector 12. The engine target rotation speed signal ne
and engine rotational speed signal N8 are input to the speed deviation detector 22. Δn8 is a deviation signal from the speed deviation detector 2.
This is the output of 2.

NoL is a left output shaft rotation speed signal, which is the output of the left output shaft rotation speed detector 13, and NoR is a right output shaft rotation speed signal, which is the output of the right output shaft rotation speed detector 14. 24 is an average speed ratio calculation circuit. the engine rotation speed signal N; and the left output shaft rotation speed signal N. L and the rotation speed N of the right output shaft. R is input to the average speed ratio calculation circuit 24. Xm is an average speed ratio signal and is the output of the average speed ratio calculation circuit 24. 25 is a speed stage logic circuit. The average speed ratio signal Xm is input to the speed stage logic circuit 25. A is each speed stage selection control signal and is an output of the speed stage logic circuit 25. 23 is a polarity addition circuit. The deviation signal Δn6 and each speed stage selection control signal A are input to the polarity adding circuit 23. Δ''eo is a polarized deviation signal and is the output of the polarization addition circuit 23. 26 is an integrator.-The polarized deviation signal ΔneO is input to the integrator 26.

Σ is a polarized deviation integral signal and is the output of the integrator 26. 27 is an adder for the left hydraulic pump, and 28 is an adder for the right hydraulic pump.

SL is separately prepared as a left output shaft steering signal. SR is separately prepared as a right output shaft steering signal. The polarized deviation integral signal Σ and the left output shaft steering signal SL are input to the left hydraulic pump adder 27. The polarized deviation integral signal Σ is input to the right hydraulic pump adder in parallel with the left hydraulic pump adder 27, and the right output shaft steering signal SR is also input to this right hydraulic pump adder.输 is the left hydraulic pump discharge amount control signal, which is the output of the adder 27 for the left hydraulic pump.

DR is a right hydraulic pump discharge amount control signal and is the output of the right hydraulic pump adder 28. The left oil pump discharge amount control signal DL is the left hydraulic pump discharge amount control actuator 7K.
, the front right hydraulic pump discharge amount control signal DR is input to the right oil pump discharge amount control actuator 8. Each speed stage selection control signal A is connected to each speed stage selection actuator 9.
is input.

Next, the operation of the above embodiment will be explained. A hydrostatic hydraulic system for tracked vehicles that has one input shaft 4 and two sets of left and right hydraulic I/O motors 17 and 18, and is configured to perform speed change and steering at the same time.
In the mechanical continuously variable transmission steering system, the average speed ratio defined below can be arbitrarily selected within the range from 0 to a certain value. If the left and right output shafts are forcibly reverse-driven from the outside and the engine is running at a certain number of revolutions, such as when driving with the accelerator pedal returned to reduce the engine output when exiting the vehicle, the left and right By controlling the average speed ratio by adjusting the discharge amount of the hydraulic pump, it is possible to reversely control the engine speed. This means that the degree of engine braking can be arbitrarily selected by controlling the average speed ratio Xm at any vehicle speed. The main parts of an embodiment of the present invention will be explained with reference to a block diagram in FIG.

When the brake pedal position signal a is input to the engine brake setting device 21, the engine brake setting device 21 has previously stored the engine target rotation speed corresponding to the brake pedal position signal a, so that the brake pedal position signal a is input to the engine brake setting device 21. An engine target rotation speed signal ne corresponding to the position signal a is output and transmitted to the speed deviation detector 22. The engine speed signal N1 is also input to a speed deviation detector, and the speed deviation detector 22 can output a deviation signal Δn8. Δn8==lno−N, l. The deviation signal Δne is input to the polarity adding circuit 23. The left output shaft rotational speed signal N. L and the right output shaft rotation speed signal NoR
and the engine speed signal NE are input to the average speed ratio calculation circuit 24, and the average speed ratio calculation circuit 24 calculates ±(N
10N)/N is calculated and output.

2 0L OR* This output is the average speed ratio signal Xm. That is, Xm-7 (NoL + NoR)/NP. The average speed ratio signal Xm is input to the speed stage logic circuit 25. Since the width (range) of the value of the average speed ratio Xm is unique in each speed stage, the speed logic circuit 25 uses the input average speed ratio signal Xm to determine in which speed stage the current average speed ratio is located.
: Select based on actuator 9 for selecting each speed stage.
Each speed stage selection control signal A is used to select a speed stage.
Output. Each speed stage selection control signal A is also input to the polarity adding circuit 23. The polarity adding circuit 23 adds either positive or negative polarity or O polarity to the deviation signal Δn8 depending on the state of each input speed stage selection signal A to generate a polarized deviation signal Δ.
"Output eo.

Here, the polarity added by the polarity adding circuit 23 is determined in the direction in which the average speed ratio ) (Engine speed signal N,) < (Engine target speed signal n), the average speed ratio Xm decreases (C) (Engine speed signal N,) - (Engine target speed signal n) In the case of , the average speed ratio xm is added so as to maintain the original value.

The polarized deviation signal Δn is input to the integrator 26.

The integrator 26 outputs the polarized deviation integral signal Σ. The polarized deviation integral signal Σ is input in parallel to an adder 27 for the left hydraulic pump and an adder 28 for the right hydraulic pump. The left hydraulic pump adder 27 adds the polarized deviation integral signal Σ to the left output shaft steering signal S, which is input separately, and outputs a left hydraulic pump discharge amount control signal DL. That is, DL-
It is Σ ten ten. The right hydraulic pump adder 28 adds the polarized deviation integral signal Σ and the separately inputted right output shaft steering signal SR to obtain the right hydraulic pump discharge amount control signal DR.
Output. That is, DR=Σ1SR.

The left hydraulic pump discharge amount control signal DL is input to the left hydraulic pump discharge amount control actuator 7, and the right hydraulic pump discharge amount control signal DR is input to the right hydraulic pump discharge amount control actuator 8. The discharge amount of the left hydraulic pump 17a is controlled by the action of the left hydraulic I pump discharge amount control actuator 70, thereby controlling the rotation speed of the left hydraulic motor 17b and the rotation speed of the left output shaft 5.

The discharge amount of the right hydraulic cylinder 7' 18a is controlled by the action of the right hydraulic pump discharge amount control actuator 8, which controls the rotation speed of the right hydraulic motor 18b, thereby controlling the rotation speed of the right output shaft 6. .

As mentioned above, the polarized deviation signal Δ”eo is (d) (engine speed signal Ng)>(engine target speed signal n8)
In this case, the left hydraulic pump discharge amount control signal DL and the right hydraulic pump discharge amount control signal DR are output in the direction of increasing the average speed ratio Xm, thereby acting to decrease the engine speed.

(e) In the case of (engine rotation speed signal N,) ((engine target rotation speed signal ne), the left hydraulic pump discharge amount control signal DL and the right hydraulic pump discharge amount control signal DR have an average speed ratio Xm. It is output in the direction of decreasing, thereby acting to increase the engine speed.

(f) In the case of (engine rotation speed signal N,) - (engine target rotation speed signal ne), the left hydraulic pump discharge amount control signal DL and the right hydraulic pump discharge amount control signal DR are such that the average speed ratio - is The output is made to maintain the same value, thereby keeping the engine speed constant.

Through the processes of (d), (e), and (f) above, the actual engine speed is converged to the target engine speed, so it is possible to arbitrarily select the engine braking force by operating the position of the brake pedal. becomes.

An embodiment in which this brake device is applied to a moon-shaped hydrostatic-mechanical continuously variable transmission steering device (Japanese Patent Application No. 58-223178) with variable speed steering function will be described with reference to FIG. 1
is a brake device, 2A is a static oil type that also has a variable speed steering function,
This is a fist mechanical continuously variable speed steering system (r14) of Japanese Patent Application No. 58-223178. 3 is the engine (
4 is the input shaft, 5 is the left output shaft, and 6 is the right output shaft. 17A is a variable displacement left hydraulic pump, and 18A is a left hydraulic motor connected to the right hydraulic pump 17A through a hydraulic pipe. 1.9A is a variable displacement right hydraulic pump, 2OA
is a right hydraulic motor connected to the right hydraulic pump 2OA through a hydraulic pipe. The left hydraulic pump 17A, left hydraulic motor 18A, right hydraulic pump 19A, and right hydraulic motor 2OA are elements of the hydrostatic-mechanical continuously variable speed steering system 2A. The left hydraulic pump 17A and the right hydraulic pump 19A are driven by the engine 3 via a transmission mechanism.

21, A, 22 A, 23 A, 24A
are a hydraulically operated clutch for the first speed stage to a hydraulically operated clutch for the fourth speed stage, respectively. 9a, 9b, 9c, 9d
are the elements of each speed stage selection actuator 9, which are the first speed stage selection actuator to the fourth speed stage selection actuator.

The first speed selection actuator 9a is the first speed hydraulically operated clutch 21A, and the second speed selection actuator 9b is the second speed hydraulically operated clutch 21A.
2A, the third speed selection actuator 9c is connected to the third speed hydraulically operated clutch 23A, and the fourth speed selection actuator 9d is connected to the fourth speed hydraulically operated clutch 24, A. ing. Aa, A
b.

Ac and Ad are inside each speed stage selection control signal A, and A
a is the first speed selection signal to the first speed selection actuator 9a, Ab is the second speed selection signal to the second speed selection actuator 9b, and Ac is the third speed selection signal to the third speed selection signal. Ad is the fourth stage selection actuator 9c.
4th speed gear selection actuator 9d with the speed gear selection signal
are connected to each.

Next, the operation of the embodiment described above will be explained with reference to FIGS. 1 to 5. The selection of each speed stage of the brake device 1 can be performed as follows. When selecting the first speed stage,
The speed stage selection control signal Aa is output, and this is transmitted to the first speed stage selection actuator 9a, which selectively engages the first speed stage hydraulically actuated clutch 21A. This can be done by fixing one gear in the planetary gear train, which is shown in the figure but not numbered. To select the second speed, when the speed selection signal Ab is output, this is transmitted to the second speed selection actuator 9b, which selectively engages the second speed hydraulically actuated clutch 22A. This can be done by operating another gear in the planetary gear train. The third speed stage and the fourth speed stage are also the same, so their explanation will be omitted. As described above, continuously variable shifting and steering can be performed simultaneously within each speed stage by the left hydraulic pump discharge amount control signal DL and the right hydraulic pump discharge amount control signal DR. 4 is a diagram showing the relationship between the discharge amount GL of the right hydraulic pump 17A, the discharge amount GR of the right hydraulic pump 19A, and the average speed ratio Xm. The left output shaft speed ratio XR and the right output shaft speed ratio XR are respectively defined by the following equations.

Then, the average speed ratio xm is x” (XL (-xR) becomes.

Discharge amount GL of the left hydraulic bong 7°17A and the right bong 7
When the discharge amount GR of °19A has the relationship shown in FIG. 4, that is, when the left hydraulic pump 17A discharge amount GL is on the pump reverse side and the right hydraulic pump 19A discharge amount GR is on the pump reverse side, Or, conversely, when the discharge amount of the left hydraulic pump 17A is on the reverse rotation side and the discharge amount GR of the right hydraulic pump 19A is on the forward rotation side, the polarity adding circuit 23 adds the polarity shown in FIG.

〔Effect of the invention〕

This invention relates to a brake device used in a hydrostatic mechanical continuously variable speed steering system for tracked vehicles that has two sets of left and right hydraulic pump motors and is capable of speed change and steering at the same time. A position detector is provided, and the output brake pedal position signal is inputted to an engine brake setting device that stores the engine target rotation speed corresponding to the brake pedal position signal in advance, thereby controlling the engine output from the engine brake setting device. The target rotational speed signal and the engine rotational speed signal output from the engine rotational speed detector provided on the input shaft are input to a speed deviation detector, and the engine target rotational speed signal and the engine rotational speed output from the speed deviation detector are detected. The deviation signal, which is the absolute value of the signal difference, is input to the polarity addition circuit, and the polarity addition circuit adds the polarity corresponding to the current speed stage to this and outputs the deviation signal with polarity, which is input to the integrator. Then, the output of the integrator is input in parallel to the adder for the left hydraulic pump and the adder for the right hydraulic pump, and the separately prepared left output shaft steering signal is input to the adder for the left hydraulic pump. The output of the pump adder is used as the left hydraulic pump discharge amount control signal, and the separately prepared right output shaft steering signal is input to the right hydraulic pump adder, and the output of the right hydraulic pump adder is used as the left hydraulic pump discharge amount control signal. Since it is used as a discharge amount control signal,
By inputting these left hydraulic pump discharge rate control signals to the left hydraulic pump discharge rate control actuator and inputting the right hydraulic pump discharge rate control signal to the right hydraulic pump discharge rate control actuator, the actual engine rotation speed can be adjusted to the engine target. Since it is possible to converge to the rotation speed, it is possible to operate both the engine brake force and the service brake by operating only the brake pedal, no matter what speed the vehicle is at.

Therefore, the present invention can provide a brake device that can perform both engine braking and service braking using only the brake pedal.

[Brief explanation of drawings]

Figure 1 is a block diagram of the transmission steering device, Figure 2 is an explanatory diagram,
Figure 4 is a diagram showing the relationship between the left hydraulic pump discharge amount, the right pump discharge amount, and the average speed ratio, Figure 5 is a diagram showing the polarity added by the polarity addition circuit, and Figure 6 is a diagram showing the relationship between the left hydraulic pump discharge amount, the right pump discharge amount, and the average speed ratio. It is an action explanatory diagram. DESCRIPTION OF SYMBOLS 1... Brake device, 2... Hydraulic-mechanical continuously variable speed steering device, 3... Ennon, 7, 8... Left and right actuators, 10... Brake target, (17a
, 17b)...Left hydraulic pump, motor, (18a',
18b)... Right hydraulic pump, motor, 21... Engine brake setting device, 22... Speed deviation detector, 23
...Polarity addition circuit. 26... Integrator, 27.28... Adder, No...
・Engine speed signal, n8... Engine target speed signal, Δn8... Deviation signal, Δ"eo... Deviation signal with polarity, 5R1S□7... Steering signal, DRlDL・
...Operation signal.

Claims (1)

[Claims] A hydraulic-mechanical continuously variable speed steering system for vehicles that simultaneously performs speed change and steering using two sets of left and right hydraulic pumps and motors.In a vehicle hydraulic-mechanical continuously variable speed steering system, the target rotation of the engine corresponds to the amount of depression of the brake pedal. a speed deviation detector that calculates the deviation between the detected value of the engine rotation speed and the target rotation speed; and a polarized deviation detector that calculates the deviation between the detected value of the engine rotation speed and the target rotation speed, It has a polarity addition circuit that outputs a polarity addition circuit, an integrator that integrates the polarized deviation, and a pair of adders that adds the integrated value and a steering signal of the vehicle and outputs an operation signal to the left and right actuators. Brake device for tracked vehicles.