JPH0658410A - Stopping control device for industrial vehicle provided with radial cylinder variable capacity pump/motor - Google Patents

Abstract

PURPOSE:To stop a vehicle in response to abrupt requirement of a driver, pre vent generation of shock at the stopping time, and obtain satisfactory stoppage feeling in respect to an industrial vehicle provided with a radial cylinder vari able capacity pump motor. CONSTITUTION:A driving shaft 3a of a hydraulic pump 3 for running is drivingly connected to an output shaft of an engine 1. An output shaft 4a of a hydraulic motor 4 is connected to a driving wheel 7 through a driving shaft 5 and an operation gear mechanism 6. In case that abrupt stopping requirement is made from a driver, that is, a braking pedal 43 is operated by more than a specified rate during running, a controller 61 functions so as to increase driving speed of a stepping motor 29A, and a transmission ratio is speedily approaches a zero value. Immediately before stopping, however, the driving speed of the stepping motor 29A is decreased, and the vehicle is slowly stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop control device for an industrial vehicle, and more particularly to a radial cylinder type variable displacement pump /
The present invention relates to a stop control device for an industrial vehicle that runs by rotating drive wheels with a motor.

[0002]

2. Description of the Related Art In some industrial vehicles such as forklifts and skid steer loaders equipped with a hydraulic device, wheels are driven by hydraulic motors (for example, actual flat blade 1-68).
924). In this type of vehicle, a hydraulic motor is rotated by operating oil supplied from a variable displacement pump that is rotationally driven by an engine, and the amount of oil supplied to the motor, that is, the displacement of the variable displacement pump, is changed to The rotation speed is controlled to control the vehicle speed.

Conventionally, a swash plate type axial piston pump / motor is generally used as the variable displacement pump / motor. However, the swash plate type axial piston pump / motor has the following problems due to the mechanism of converting pressure into torque. That is, in the swash plate type axial piston pump / motor, the piston side pressure is generated at the cylinder front edge and the piston rear end due to the overhang of the piston tip, and the side pressure at the piston rear end opposes the effective output torque. These side pressures become frictional forces, which adversely affect the torque performance during start-up / low speed operation and impair the controllability. However, in the swash plate type motor, the rotational force is transmitted to the output shaft by the piston side pressure.

As a variable displacement pump / motor that solves the problems of the swash plate type axial piston pump / motor, a new radial cylinder type variable displacement pump / motor of FFC (FLUID FORCE COUPLE) system has been proposed (Kita, hydraulic pressure. And Air Pressure, Vol. 20, No. 2 (1989), 7-1
4. ). This variable displacement pump / motor is basically composed of a cylindrical casing and seven planes which are in contact with the inner surface of the casing by seven static pressure pads provided on the outer periphery and whose inner surface corresponds to the static pressure pads. Coupling ring, a seal bush (piston) perpendicularly contacting each plane inside the couple ring, a cylinder block having seven radial cylinders that fit with the seal bush, and a center hole of the cylinder block. It is composed of pintles which are eccentric to the casing center and can be eccentric in the direction perpendicular to the axis. The displacement of the pump or the output of the hydraulic motor changes according to the amount of eccentricity of the pintle. It is considered that the FFC type variable displacement pump / motor is used in an industrial vehicle instead of the swash plate type axial piston pump / motor.

[0005]

However, the above-mentioned FFC
In a vehicle equipped with a variable displacement pump / motor,
No means for changing the speed at which the pintle is eccentric is adopted, and the eccentric speed of the pintle is always constant. Therefore, for example, when stopping the vehicle,
Even if the driver demands to decelerate and stop the vehicle particularly quickly, the demand cannot be met because the eccentric speed of the pintle is always constant.

Further, when there is a prompt deceleration request from the driver as described above, the eccentric speed of the pintle is increased in order to meet the request, and the pintle is drive-controlled so that the eccentric amount becomes zero quickly. It is possible to do it.

However, in the above control, the eccentric speed of the pintle becomes high until the amount of eccentricity becomes zero, that is, until the vehicle stops. For this reason, when the vehicle speed becomes zero, that is, the shock at the time of stopping becomes large, which may impair the driver's feeling when stopping.

The present invention has been made in view of the above problems, and an object thereof is to stop an industrial vehicle equipped with a radial cylinder type variable displacement pump / motor in response to a prompt stop request from a driver. Is possible, and
An object of the present invention is to provide a stop control device capable of preventing a shock at the time of stopping and experiencing a good feeling at the time of stopping.

[0009]

To achieve the above object, in the present invention, there are provided a radial cylinder type variable displacement pump / motor driven by an engine to drive driving wheels, and the variable displacement pump / motor. A pintle drive means that is provided to change the eccentricity of the pintle that is displaced to control the gear ratio of the vehicle, and accelerator opening detection that detects the operation amount of the accelerator pedal that is operated to control the opening of the throttle valve Means, valve driving means for driving the throttle valve to open and close, target opening calculation means for calculating a target opening of the throttle valve based on the detection result of the accelerator opening detection means, and the target opening calculation means. Valve drive control means for driving and controlling the valve drive means based on the calculated target opening, and a target calculated by the target opening calculation means In the industrial vehicle provided with the radial cylinder type variable displacement pump / motor having the pintle drive control means for controlling the drive of the pintle drive means based on the degree, when the driver makes a sudden stop request, the stop A pintle drive speed control means for driving the pintle drive means at a speed faster than when there is no request; a pintle eccentricity amount detection means for detecting an eccentricity amount of the pintle; and a detection result of the pintle eccentricity amount detection means. When the eccentric amount of the pintle is near zero, a second pintle drive speed control means for driving the pintle drive means at a speed slower than the drive speed by the pintle drive speed control means is provided. The gist is a stop control device for an industrial vehicle equipped with a cylinder type variable displacement pump / motor. There.

[0010]

According to the above construction, the operation amount of the accelerator pedal is detected by the accelerator opening detecting means. The target opening calculation means calculates the target opening of the throttle valve based on the detection result of the accelerator opening detection means. Then, based on the target opening calculated by the target opening calculation means,
The valve drive control means drives and controls the valve drive means to open and close the throttle valve. As a result, the engine speed is changed.

Further, the pintle drive control means drives and controls the pintle drive means based on the target opening degree calculated by the target opening degree calculation means. Therefore, the variable displacement pump /
The eccentric amount of the pintle provided on the motor is changed, and the displacement of the pintle controls the gear ratio of the vehicle. The rotation of the engine is transmitted to the drive wheels via the radial cylinder type variable displacement pump / motor according to the gear ratio.

On the other hand, when there is a sudden stop request due to the driver's request during traveling, the pintle drive speed control means drives the pintle drive means at a speed faster than when there is no stop request. Therefore, the pintle is driven at high speed so that the amount of eccentricity becomes zero, and the vehicle is quickly decelerated.

The pintle eccentricity detecting means detects the eccentricity of the pintle. Then, when the amount of eccentricity based on the detection result is near zero, the second pintle drive speed control means drives the pintle drive means at a speed slower than the drive speed by the pintle drive speed control means. Therefore, when the vehicle is stopped, the driving speed of the pintle becomes slow, and the eccentric amount of the pintle slowly becomes zero. Therefore, less impact is required when the vehicle is stopped.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a forklift will be described below with reference to the drawings.

As shown in FIG. 1, an output shaft of an engine 1 mounted on a vehicle (not shown) has a drive shaft 3a of a hydraulic pump 3 constituting a radial cylinder type variable displacement pump / motor 2 for traveling. Are drivingly connected. An output shaft 4a of a hydraulic motor 4 that constitutes the variable displacement pump / motor 2 is connected to a drive wheel 7 via a drive shaft 5 and an operating gear mechanism 6. The vehicle travels along with the rotation of the output shaft 4a. Further, the drive shaft 3a is
A hydraulic pump (not shown) for supplying hydraulic oil to a lift cylinder (not shown) for cargo handling work is driven.

In this embodiment, since the hydraulic pump 3 and the hydraulic motor 4 have basically the same structure, the structure of the hydraulic motor 4 will be described as an example. As shown in FIGS. 2 to 4, a couple ring 10 is housed in a housing space surrounded by a cylindrical casing 8 and a rear cover 9 that covers an opening thereof. The couple ring 10 is formed integrally with the output shaft 4a protruding outside the casing 8,
The output shaft 4a is connected to the drive shaft 5 via a coupling (not shown) in the spline 4b.

The couple ring 10 has a bearing 11
It is rotatably supported by the casing 8. Seven shoes (static pressure pads) 12 are attached to the outer circumference of the couple ring 10 at equal intervals so as to rotate integrally with the couple ring 10 (see FIG. 4). Planes 10a are formed on the inner surface of the couple ring 10 at seven locations corresponding to the shoes 12. Further, the couple ring 1 is provided at the center of each plane 10a.
A hole 10b penetrating 0 is formed. Further, a hole 12a penetrating the shoe 12 is formed in the center of the shoe 12.

The rear cover 9 includes a cylinder block 13
The pintle 14 that supports the shaft is movably supported in a direction orthogonal to the axis of the output shaft 4a. As shown in FIGS. 3 and 5, the pintle 14 has a groove 9 a formed in the rear cover 9.
It is composed of a pedestal portion 14a having a trapezoidal prismatic cross section that fits into the pedestal portion, and a truncated conical support portion 14b provided on the pedestal portion 14a so as to project into the couple ring 10. The cylinder block 13 has a fitting hole 13 formed at the center thereof.
By fitting a to the support portion 14b, the pintle 14
Is rotatably supported with respect to.

The pintle 14 has a pair of ports 14c and 14d formed on the peripheral surface of the support portion 14b and a pedestal portion 14a.
A pair of oil passages 15 and 16 which respectively communicate with a pair of ports 14e and 14f formed on the slope are formed to cross each other like a plow. As shown in FIG. 3, one oil passage 15 is connected to the low pressure port 17B formed in the rear cover 9, and the other oil passage 16 is connected to the rear cover 9.
Is connected to the high-pressure port 18B formed in.

Seven cylinder bores 19 are formed in the cylinder block 13 at equal intervals in a direction orthogonal to the peripheral surface of the support portion 14b so as to communicate with the oil passages 15 and 16. In the cylinder bore 19, a piston 20, which is held with its one end in contact with the flat surface 10a, is reciprocally housed. Each of the shoes 12 and the piston 20 is formed so that the maximum pressure receiving area becomes equal. The cylinder block 13 is connected to the couple ring 10 by an Oldham's joint 21 so as to be rotatable integrally therewith.

As shown in FIG. 2, the groove 9 is formed in the pedestal portion 14a.
A servo spool 22 extending along the longitudinal direction of a (the vertical direction in FIG. 2) is attached so as to be movable integrally with the pintle 14. The servo spool 22 is inserted into a hole 23 formed in the pedestal portion 14a with its tip protruding. The servo spool 22 is urged downward in the drawing by a spring 24 interposed between a flange 22a formed at the base end of the servo spool 22 and the end of the hole 23. The stop ring 25 fixed to the tip of the servo spool 22 comes into contact with the outer surface of the pedestal portion 14a, so that the downward movement thereof is restricted. Therefore, the servo spool 22 moves integrally with the pintle 14 until a force larger than the biasing force of the spring 24 acts on the servo spool 22 in the direction opposite to the biasing force.

An accommodating portion 26 is formed in the rear cover 9 at a position corresponding to the groove 9a, and a control rod 27 for driving the pintle 14 via the servo spool 22 is accommodated in the accommodating portion 26. . The control rod 27 penetrates a hole 9b communicating with the groove 9a, and its tip is screwed to the base end of the servo spool 22. In addition, the control rod 27 has a housing portion 2
A guide rod 28 protruding in parallel with the axial direction of the servo spool 22 is inserted into the shaft 6, and the control rod 27 is movable along the guide rod 28.

Further, a step motor 29B is fixed to the rear cover 9 so as to cover the opening of the accommodating portion 26. A male screw 30 is attached to the output shaft 30 of the step motor 29B.
a is formed, and the male screw 30a is attached to the control rod 27.
Is screwed into the screw hole 27a formed in the. Therefore,
With the forward and reverse rotation of the output shaft 30, the control rod 27
2 moves in the vertical direction in FIG. 2, and the pintle 14 moves along the groove 9a via the servo spool 22. Then, the servo spool 22, the control rod 27 and the step motor 29B constitute a pintle driving means for driving the pintle 14 in a direction orthogonal to its axis.

A pintle position sensor 31 composed of a potentiometer for detecting the position of the pintle 14 is provided in the accommodating portion 26.
B is provided. The pintle position sensor 31B is connected to the control rod 27, and the position where the eccentricity amount δ1 of the pintle 14 is 0, that is, the center of the output shaft 4a and the support portion 1 are arranged.
The position at which the center of 4b coincides with the reference position (neutral position) is used to detect how much the pintle 14 has moved from the neutral position.

Now, as described above, the hydraulic pump 3 is
The hydraulic motor 4 has the same mechanical structure.
That is, the pintle 32 on the hydraulic pump 3 side is driven by the step motor 29A in the direction orthogonal to its axis. Further, the position of the pintle 32 is detected by a pintle position sensor 31A composed of a potentiometer. Then, the hydraulic pump 3 and the hydraulic motor 4 are connected to each other via a pipe line (not shown) to form the low-pressure port 17 of each other.
A and 17B are connected to each other and high pressure ports 18A and 18B are connected to each other (see FIGS. 2 to 5).

Next, the hydraulic pump 3 and the hydraulic motor 4
The operating principle of will be described in detail. First, in the hydraulic motor 4, as shown in FIG. 4, when hydraulic oil is introduced into the cylinder bore 19, the piston 20 pushes the flat surface 10 a toward the outside of the couple ring 10. Each plane 10a at the same time
The hydraulic oil is guided to the outside of the shoe 12 through the hole 10b formed in the center and the hole 12a formed in the shoe 12. This hydraulic oil pushes the couple ring 10 inward. The force of pushing the couple ring 10 from the inside and the outside with hydraulic oil causes the couple ring 10 to receive a couple force by a hydraulic pressure on one side thereof in a size proportional to the eccentric amount of the cylinder bore 19. Then, an output torque proportional to the value obtained by multiplying the pressure of the three cylinder bores 19 communicating with the high pressure port 18B by the sum of the eccentricity amounts is obtained. That is, for example, in the state of FIG. 4, when the upper cylinder bore 19 has a high pressure, the couple ring 10 can obtain a rotational force corresponding to the sum of the couples. The figure rotates clockwise. As a result, the output shaft 4 of the hydraulic motor 4
a is rotated.

When the eccentricity δB of the pintle 14 is 0, that is, when the pintle 14 is in the neutral position, the sum of the couples applied to the couple ring 10 becomes zero, so that the output torque is 0. Becomes Therefore, the output shaft 4a of the hydraulic motor 4 is held in a non-rotating state. Further, when the pintle 14 is moved to the upper side from the position shown in FIG. 2 and further moved to the upper side from the position where the eccentricity amount δB becomes 0, the rotation direction of the couple ring 10 becomes the opposite direction to that, and the output The rotation direction of the shaft 4a is also the reverse direction. However, in the apparatus of this embodiment, the eccentricity amount δB of the pintle 14 is changed only on the plus side (see FIG. 6).

Next, in the hydraulic pump 3, the drive shaft 3
When a is driven, the couple ring 10 and the cylinder block 13 are synchronously rotated. Then, the couple ring 10 presses the pistons 20 in the three cylinder bores 19 in communication with the oil passage 16 communicating with the high pressure port 18A corresponding to the eccentricity δA on the plus side of the pintle 32, and the inside of the cylinder bore 19 is pressed. Pressure is applied to the hydraulic oil. Then, the hydraulic oil in the cylinder bore 19 in a state corresponding to the oil passage 16 is supplied to the hydraulic motor 4 via the high pressure port 18A.

On the other hand, when the position of the pintle 32 is moved to the side opposite to that of FIG. 4 with respect to the neutral position (when the eccentricity δA of the pintle 32 is on the negative side), even if the rotation direction of the drive shaft 3a is the same, The couple ring 10 is connected to the low pressure port 17A and is connected to the piston 20 in the three cylinder bores 19.
Press. Therefore, contrary to the above, high-pressure hydraulic oil is supplied to the hydraulic motor 4 from the low-pressure port 17A side. Then, the rotation direction of the hydraulic motor 4 is reversed, and the forklift moves backward.

When the stepper motors 29A and 29B are driven to rotate the output shaft 30, the control rod 27 screwed onto the output shaft 30 is moved along the guide rod 28 in the vertical direction of FIG. When the control rod 27 moves, the pintle 14, via the servo spool 22,
32 moves integrally. The movement direction of the control rod 27 corresponds to the rotation direction of the output shaft 30, and the movement amount is proportional to the rotation amount of the output shaft 30.

In this embodiment, as shown in FIG. 6, the pintle 14 of the hydraulic motor 4 operates in a low speed range during forward travel and during reverse travel (vehicle speed V is -8 to 8 km / h in this embodiment). The eccentricity amount δB is fixed so as to be maximum (7.5 mm). On the other hand, the pintle 32 of the hydraulic pump 3 is
In this region, when the vehicle speed V is zero, the eccentricity amount δ
When A is zero, the amount of eccentricity δA increases in proportion to the vehicle speed V.

In addition, the pintle 14 of the hydraulic motor 4 has a high speed region when moving forward (in this embodiment, the vehicle speed V is 8 to 20 km /
In h), the eccentricity amount δB decreases from the maximum state as the vehicle speed V increases. On the other hand, the pintle 32 of the hydraulic pump 3 is fixed so that the eccentricity amount δA becomes maximum (7.5 mm) in this region.

Therefore, the rotational speed of the couple ring 10 of the hydraulic motor 4 becomes lower than the rotational speed of the couple ring 10 of the hydraulic pump 3 in the low speed region when moving forward and in the reverse direction.
On the contrary, in the high speed region, the rotational speed of the couple ring 10 of the hydraulic motor 4 is higher than that of the couple ring 10 of the hydraulic pump 3. That is, the gear ratio RF between the hydraulic motor 4 and the hydraulic pump 3 (the couple ring 1 of the hydraulic motor 4 is
0 rpm / rotational speed of couple ring 10 of hydraulic pump 3)
Is smaller in the low speed region and larger in the high speed region. Further, the boundary between the low speed region and the high speed region, that is, the vehicle speed V is 8
The gear ratio RF is "1" at km / h.

In this embodiment, in addition to the pintle position detecting sensors 31A and 31B, various sensors described below are provided. That is, as shown in FIG. 1, the accelerator pedal 41 is provided with an accelerator sensor 42 as an accelerator opening detection means for detecting an accelerator opening ACC corresponding to the depression amount, and the brake pedal 43 is provided with a brake depression. A brake sensor 44 is provided as a brake operation amount detecting means for detecting the amount BRK. Also,
A lift sensor 45, which detects the amount of operation of the lift lever 45 that is operated when moving up and down a fork (not shown), is provided in the tilt lever 47 that is operated when tilting the fork back and forth. A tilt sensor 48 for detecting the operation amount is provided.

Further, a feeling adjusting knob 49 as a feeling adjusting member operated when adjusting the sensitivity at the time of deceleration of the forklift has an operation amount (SOFT).
(To HARD) is provided with a knob sensor 50 as an adjustment amount detecting means. In addition, a throttle valve (not shown) provided in the engine 1 and driven to open and close by the valve step motor 51 is provided with a throttle opening sensor 52 that detects the degree of opening and closing.
Each of these sensors 42, 44, 46, 48, 50, 52 is composed of a potentiometer.

Further, the forward / backward lever 53, which is operated when switching the forward or reverse of the forklift, is provided with a shift sensor 54 composed of a limit switch for detecting its shift position (forward / neutral / reverse). There is.
Further, the engine 1 is provided with an engine rotation speed sensor 55 including a pickup coil for detecting the rotation speed thereof. A vehicle speed sensor 56 is provided between the gear mechanism 6 and the output shaft 4a to detect the rotation speed of the drive shaft 5 to detect the vehicle speed V of the forklift.

Further, in this embodiment, a controller 61 for driving and controlling the step motors 29A, 29B and the valve step motor 51 is provided.
The controller 61 includes the sensors 31A, 31
B, 42, 44, 46, 48, 50, 52, 54, 5
Detection signals from 5, 56 are input. The controller 61 constitutes a pintle drive control means, an opening calculation means, a valve drive control means, a pintle drive speed control means, and a second pintle drive speed control means.

The controller 61 includes a CPU (central processing unit) 62, a read-only program memory (ROM) 63 that stores each control program, and a readable and rewritable work memory (where operation processing results and the like are stored). A RAM) 64, an input / output interface 65, etc. are provided.

The CPU 62 includes an accelerator sensor 42, a brake sensor 44, a lift sensor 46, a tilt sensor 48, a knob sensor 50, a throttle opening sensor 52, a hydraulic pump via the A / D converters 66 to 73 and the input / output interface 65. The pintle position sensor 31A on the side 3 and the pintle position sensor 31B on the side of the hydraulic motor 4 are connected to each other. Further, the shift sensor 54 is connected to the CPU 62 via an input / output interface 65. Further, the CPU 62 is provided with F / V converters 74, 7
5, the engine speed sensor 55 and the vehicle speed sensor 56 are connected via the A / D converters 76 and 77 and the input / output interface 65.

The CPU 62 uses the sensors 31A, 31
B, 42, 44, 46, 48, 50, 52, 54, 5
Based on the detection signals from 5, 56, the accelerator opening degree ACC, the brake depression amount BRK, or the eccentric amounts δA, δB from the neutral positions of the pintles 32, 14 on the hydraulic pump 3 side and the hydraulic motor 4 side, etc. It is designed to detect.

Step motors 29A and 29B on the hydraulic pump 3 side and the hydraulic motor 4 side are connected to the CPU 62 via an input / output interface 65 and drive circuits 78 and 79. Further, the valve step motor 51 is connected to the CPU 62 via the input / output interface 65 and the drive circuit 80. And the CPU 62
Are the sensors 31A, 31B, 42, 44, 46,
Based on the detection results from 48, 50, 52, 54, 55, 56, the step motors 29A, 29B and the valve step motor 51 are preferably controlled.

In this embodiment, R of the controller 61
The OM 63 stores various maps A to I set in advance for performing various controls, and the CPU 62 uses the step motors 29A and 29A based on these maps A to I.
29B and the valve step motor 51 are drive-controlled.

That is, the ROM 63 stores the map A shown in FIG. 7 in which the target throttle opening SLO1 for the accelerator opening ACC at each time is preset. Further, the ROM 63 stores the engine speed EN for each throttle opening SLO obtained by the experiment shown in FIG.
Based on the relationship of the shaft output ST with respect to G (hereinafter, referred to as map B for convenience of description), the target engine speed E with respect to the accelerator opening ACC at each time shown in FIG.
A map C in which NG1 is set is stored. In this map C, an engine speed ENG capable of obtaining the maximum shaft output STMAX at the accelerator opening ACC at that time based on the maps A and B is set as a target engine speed ENG1 at that time. .

Further, the ROM 63 stores PI in the feedback control for the gear ratio RF shown in FIG.
Gain [feedback coefficient KFB (KP is a differential coefficient,
KI is an integration coefficient)] and a map D in which a preset value is stored.

That is, as shown in FIG. 17, the controller 61 calculates the target throttle opening SLO1 for the accelerator opening ACC at that time based on the map A. Then, the valve step motor 51 is drive-controlled so that the throttle opening SLO becomes the target throttle opening SLO1, and the engine speed ENG is controlled.

Further, as shown in FIG. 11, the ROM 63 is divided and set based on the throttle opening SLO (corresponding to the accelerator opening ACC) and the gear ratio RF (corresponding to the eccentricity amounts δA and δB). Step motor 29A,
A map E indicating the control area of 29B is stored. In this map E, the control area is two area boundary lines,
Is divided into three regions, that is, a first feedforward control region X, a feedback control region Y, and a second feedforward control region Z.

Here, the above-mentioned area boundary line will be described. First, in map E, throttle opening SL
A point where O is zero and the gear ratio RF is zero is set as a point O. Further, the point where the throttle opening SLO is "64step" and the gear ratio RF is "0.6" is point A, and the throttle opening SL
O is "108 step (maximum)" and the gear ratio RF is "0.
The point "6" is designated as point B. The area boundary lines are points O and A.
And a line connecting point B.

Further, the throttle opening SLO is "40st
The point where the gear ratio RF is "1" at "ep" is point C, the throttle opening SLO is "72step" and the gear ratio RF is "2.
The point "5 (maximum)" is designated as point D. Further, the throttle opening SLO is “108 step” and the gear ratio RF is “2.
The point "5" is designated as point E. The area boundary line is a line connecting points O, C, D and E.

The range of the first feedforward control area X is a portion sandwiched by the horizontal axis (throttle opening SLO) of the map E and the area boundary line. Further, the range of the feedback control area Y is a portion sandwiched between the area boundary line and the area boundary line. Further, the range of the second feedforward control area Z is a portion sandwiched by the area boundary line and the vertical axis (gear ratio RF) of the map E.

Therefore, for example, it is assumed that the forklift is started by depressing the accelerator pedal 41 while the forklift is stopped, that is, when the gear ratio RF is zero. When the throttle opening SLO at this time is "60step", the gear ratio RF is zero, and therefore the controller 61 recognizes that the current region is within the first feedforward control region X. Then, the controller 61 feed-forward-controls the step motors 29A and 29B based on the map F shown in FIG. In this map F, the target gear ratio RF1 for the throttle opening SLO at that time is preset. As shown in the figure, when the throttle opening SLO is between "0 and 64 step", the target gear ratio RF1 increases with the increase of the throttle opening SLO. In addition, the throttle opening SLO
Is larger than "64step", the target gear ratio RF1 is set to a constant "0.6" regardless of the throttle opening SLO. That is, the throttle opening SLO and the target gear ratio R in this map F
The relationship with F1 corresponds to the area boundary line in the map E of FIG. 11 (see FIGS. 11 and 12).

Further, for example, the throttle opening SLO is "7".
If the gear ratio RF is "1" in "2step", the controller 61 recognizes that the current region is within the feedback control region Y based on the map E. Then, the controller 61 determines the accelerator opening ACC (throttle opening SLO) at that time based on the map C shown in FIG.
The target engine speed ENG1 for is calculated. After that, the engine speed ENG is equal to the target engine speed ENG.
The stepper motors 29A and 29B are feedback-controlled so as to be equal to 1. That is, at this time, the step motors 29A and 29A based on the map D of FIG.
B is driven and controlled, and the eccentricity amounts δA of the pintles 32 and 14 are
δB is controlled. Therefore, the gear ratio RF is changed, and the load on the engine 1 is appropriately changed. As a result, the maximum shaft output STMAX at the accelerator opening ACC at that time is obtained.

Further, for example, when the throttle opening SLO is "40step" and the gear ratio RF is "2",
The controller 61 determines that the current area is second based on the map E.
Recognize that it is within the feedforward control area Z. Then, the controller 61 feed-forward-controls the step motors 29A and 29B based on the map G shown in FIG. This map G shows the target gear ratio RF2 for the throttle opening SLO at that time.
Is set in advance. As shown in the figure, when the throttle opening SLO is between "0-40step", the target gear ratio RF2 increases as the throttle opening SLO increases, and the throttle opening SLO becomes "40step".
When "p", the target gear ratio RF2 becomes "1". Further, when the throttle opening SLO is between "40 to 72 step", the target gear ratio RF2 is equal to the throttle opening SL.
It further increases as O increases, and the throttle opening SLO
When is “72 step”, the target gear ratio RF2 is “2.5 (maximum)”. Furthermore, the throttle opening S
When LO becomes larger than "72step",
The target gear ratio RF1 is set to be constant "2.5" regardless of the throttle opening SLO. That is,
The relationship between the throttle opening SLO and the target gear ratio RF1 on the map G corresponds to the area boundary line on the map E in FIG. 11 (see FIGS. 11 and 13).

Further, the ROM 63 stores a map H in which a coefficient Kα to be multiplied by the target gear ratio RF2 of FIG. 13 with respect to the brake depression amount BRK shown in FIG. 14 is preset. According to this map H, when the brake depression amount BRK is less than 70%, the coefficient Kα applied to the target gear ratio RF2 decreases as the depression amount BRK increases.

Therefore, as shown in FIG. 15, when the brake pedal is depressed, the target gear ratio RF2 of the map G described above is obtained.
Is multiplied by the coefficient Kα determined based on the map H. Therefore, when the brake depression amount BRK is less than 70%, the controller 61 sets the target gear ratio R
Feedforward control is performed so that F2 becomes small (from the dotted line to the solid line in FIG. 15). Therefore, the vehicle speed V at that time
The target engine speed ENG1 with respect to is higher than that when the brake pedal 43 is not depressed.

When the brake depression amount BRK is 70% or more, the controller 61 controls the eccentric amount of the pintle 32 to quickly return to zero. That is, the vehicle speed V is controlled so as to quickly become zero. However, when the accelerator pedal 41 is depressed, the engine speed ENG is held according to the accelerator opening degree ACC.

In the ROM 63, the operation position (SOFT to HAR) of the feeling adjusting knob 49 shown in FIG.
A map I in which the rotational speeds SMA and SMB of the step motors 29A and 29B for D) are preset is stored.

As shown in FIG. 17, the controller 61 changes the rotational speeds SMA and SMB of the step motors 29A and 29B at the time of deceleration according to the knob operating position at that time. That is, when the operation position of the feeling adjusting knob 49 is in SOFT, the rotation speeds SMA and SMB of the step motors 29A and 29B are the lowest (for example, 1steps / 16 ms), and when the operation position is in HARD, the step motor 29A,
The rotation speed SMA, SMB of 29B is the highest (eg 10s
(Teps / 16 ms).

When the brake depression amount BRK is equal to or greater than the predetermined amount (70%), the controller 61 controls the feeling adjusting knob 4 as described above.
9 regardless of the operating position of the step motors 29A, 29
The vehicle speed V is always controlled to be the maximum speed so that the vehicle speed V becomes zero.

As described above, in the present embodiment, the controller 61 determines that the accelerator opening ACC becomes zero or the brake depression amount BRK is 70% when the knob operating position of the feeling adjusting knob 49 is HARD. When it becomes the above, it is assumed that there is a sudden stop request from the driver, and the step motor 29 is used immediately before the stop.
The rotation speeds SMA and SMB of A and 29B are driven at the maximum speed, and the eccentricity amount δA of the pintle 32 is brought close to zero at high speed.

Here, in this embodiment, the stop control according to the present invention is performed. That is, when the pintle 32 is eccentric at a high speed and the eccentricity amount δA reaches near zero [−β ≦ δA ≦ β (see FIG. 6)], the rotation speeds SMA of the step motors 29A and 29B,
The SMB is driven at the lowest speed to reduce the eccentric speed of the pintle 32.

Next, the operation of this embodiment will be described. In the present embodiment, as described above, in addition to the engine speed control that is the main control, region control (including maximum axis output control) for each condition, inching control, deceleration feeling control, and stop control according to the present invention are also performed. The control will be described in detail below with reference to various flowcharts.

First, engine speed control (main control)
Will be described. FIG. 18 is a flow chart showing a main control processing routine executed by the controller 61 in the present embodiment, which is executed by a timed interrupt every predetermined time.

When the processing shifts to this routine, first, at step 101, the accelerator opening degree ACC at that time is read based on the detection signal from the accelerator sensor 42.

In the following step 102, the target throttle opening SLO1 for the accelerator opening ACC is calculated based on the map A in FIG. Then, in step 103, the valve step motor 51 is drive-controlled so that the current throttle opening SLO becomes the target throttle opening SLO1. Along with this, the throttle valve is opened / closed, and the engine 1 is drive-controlled based on the opening thereof. Then, the controller 61 once ends the subsequent processing.

The controller 61 performs the main control process and the area control for each condition. 19 and 20 (a), (b), and (c) are flowcharts showing the processing routine of the region control for each condition executed by the controller 61 in the present embodiment, which is executed by the regular interruption at every predetermined time. To be done.

When the processing shifts to this routine, first, at step 201, the throttle opening SLO corresponding to the accelerator opening ACC at that time is read based on the detection signal from the accelerator sensor 42 or the like.

In step 202, the eccentricity amounts δA and δB of both pintles 32 and 14 are read based on the detection signals from the pintle position sensors 31A and 31B. Next, in the throttle 203, the accelerator opening A
Throttle opening SLO and eccentricity δA corresponding to CC,
The gear ratio RF corresponding to δB is calculated, and which control region (X, Y, Z) the present belongs to is determined based on the throttle opening SLO and the gear ratio RF. Here, which region the current control region belongs to is determined based on the map E shown in FIG. 11 described above.

If the control area at that time is the first feedforward area X, the processing is performed as shown in FIG.
The routine proceeds to the first feedforward region control routine shown in (a).

When the processing shifts to this feedforward region control, first, in step 301, the process shown in FIG.
The throttle opening SLO at that time based on the map F of FIG.
The target gear ratio RF1 for is calculated.

Next, at step 302, it is judged if the throttle opening SLO at that time is less than "64step". If the throttle opening SLO is less than “64step”, the process proceeds to step 303.

In step 303, the actual gear ratio R
The step motor 29A is driven and controlled at the lowest speed so that F becomes the target gear ratio RF1 calculated in step 301, the pintle 32 is eccentric, and the subsequent processing is once ended.

If the throttle opening SLO is equal to or more than "64step" in step 302, the process proceeds to step 304. In step 304, the gear ratio RF is the target gear ratio RF calculated in step 301.
The step motor 29A is driven and controlled at the maximum speed so as to be 1, and the pintle 32 is eccentric, and the subsequent processing is once ended.

As described above, by performing the above-mentioned first feedforward control, first, when the forklift starts, the throttle opening SLO becomes "64step".
If less, that is, if the speed increase rate requested by the driver is relatively small, the step motor 29A is drive-controlled at the minimum speed. Therefore, when starting the low speed traveling, the gear ratio RF slowly increases, so that a smooth start is possible and a good fine operability can be experienced. Further, the throttle opening SLO is set to “64 ste
In the case of "p" or more, that is, when the speed increase rate requested by the driver is relatively large, the step motor 29A is drive-controlled at high speed. Therefore, in this case, the speed ratio R
F rises and it becomes possible to start quickly. Further, in this region, since the feedforward control is performed, the vehicle can be promptly started without being delayed with the depression of the accelerator pedal 41, and the response performance can be improved.

If it is determined in step 207 of the region control for each condition of FIG. 19 that the feedback region control is performed, the process proceeds to the feedback region control routine of FIG. 20 (b).

When the processing shifts to this feedback region control, first, at step 401, the target engine speed ENG1 for the accelerator opening ACC read at step 202 is calculated based on the map C. Here, the calculated target engine speed ENG1
Is the rotational speed at which the maximum shaft output STMAX at the accelerator opening ACC (throttle opening SLO) at that time can be obtained.

In the following step 402, the read actual engine speed ENG is equal to the target engine speed EN.
The step motors 29A and 29B are feedback-controlled so as to attain G1. That is, at this time, the step motors 29A and 29B are drive-controlled while referring to the map D. Then, the subsequent processing is temporarily terminated.

In this way, the step motors 29A, 29
By controlling B to be driven, the eccentric amounts δA and δB of the pintles 32 and 14 are appropriately controlled. Therefore, the gear ratio RF is changed, and the load applied to the engine 1 is appropriately changed. Therefore, the engine speed ENG controlled in the main control is changed to the target engine speed ENG1, and as a result, the maximum shaft output STMAX at the accelerator opening ACC at that time can be obtained.

If it is determined in step 207 of the condition-based area control routine that the area is in the second feedforward control area, the process proceeds to the second step in FIG. 20 (c).
Move to the feedforward control routine.

When the processing shifts to this routine, first,
In step 501, based on the map G of FIG. 13, the target gear ratio R with respect to the throttle opening SLO at that time
Calculate F2. Then, in the following step 502, the step motors 29A and 29B are feedforward-controlled at high speed so that the gear ratio RF becomes the target gear ratio RF2 calculated in step 501, and the subsequent processing is temporarily terminated.

As described above, in the second feedforward control routine, the target gear ratio RF1 is controlled on the region boundary line which is the upper limit of the feedback control region. Therefore, after the start of traveling, the gear ratio RF does not become maximum even though the throttle opening SLO is low. As a result, it is possible to prevent the vehicle speed V from rapidly increasing, which is not intended by the driver, and the operability can be greatly improved.

Next, inching control during traveling will be described. FIG. 21 is a flowchart showing a processing routine of inching control executed by the controller 61 in the present embodiment, and this processing is executed during traveling.

When the processing shifts to this routine, first in step 601, the pintle position sensors 31A, 3
Based on the detection result of 1B, the eccentricity amounts δA and δB of the pintles 32 and 14 are read. In the next step 602, the brake depression amount BRK is read based on the detection result of the brake sensor 44. Then, in step 603, it is determined whether or not the brake depression amount BRK is less than 70%. When the brake depression amount BRK is less than 70%, the process proceeds to step 604. Step 60
4, the coefficient Kα is calculated based on the map H.
The coefficient Kα is a value by which the target gear ratio RF2 of the map G is multiplied.

Next, at step 605, a coefficient K determined based on the map H is set for the target speed ratio RF2.
Multiply by α and set the value as a new target gear ratio RF2.

Then, in step 606, the step motors 29A and 29B are drive-controlled so that the gear ratio RF becomes the target gear ratio RF2. That is, the controller 61 feed-forward-controls the step motors 29A and 29B so that the value thereof becomes smaller than the target gear ratio RF2 at the time of the second feed-forward control described above, and temporarily terminates the subsequent processing.

On the other hand, in step 603, when the brake depression amount is 70% or more, the routine proceeds to step 607, where it is judged that there is a sudden stop request from the driver, and the target gear ratio RF1 or Set RF2 to zero.

Then, in step 608, the step motor 29A is driven and controlled at high speed so that the eccentricity δA of the pintle 32 on the hydraulic pump 3 side becomes zero. Next, in step 609, based on the detection result of the pintle position detection sensor 31A, it is determined whether or not the eccentricity amount δA reaches near zero, that is, whether or not the eccentricity amount δA is −β or more and β or less. To judge. When it is determined that the eccentricity amount δA is −β or more and β or less, the process proceeds to a stop routine described later. on the other hand,
When it is determined that the eccentricity amount δA is not less than −β and not less than β, the subsequent processing is temporarily terminated.

Next, description will be made on the processing when the process shifts to the stop routine. FIG. 22 is a flowchart showing the stop routine. In this stop routine,
First, in step 701, the eccentricity amount δ of the pintle 32 is
It is determined whether A is zero. And the eccentricity δA
If is zero, the vehicle is considered to have been stopped, and the subsequent processing is temporarily terminated. Further, when the eccentricity amount δA is not zero, it is assumed that the step motors 29A and 29B are not yet stopped, and the rotation speeds SMA and SMB of the step motors 29A and 29B are next time.
(Substantially only the rotation speed SMA of the step motor 29A) is set to the minimum speed. As a result, immediately before the stop, the eccentric speed of the pintle 32 becomes slow, and the forklift slowly moves toward the stop. Then, this stop routine is repeated until the forklift stops.

As described above, in the inching control and the stop-time control of this embodiment, for example, so-called inching traveling, in which the cargo handling work (the operation of operating the lift lever or the tilt lever to raise and lower and tilt the fork) is performed while traveling. In the case of performing, the inching control described above is performed by depressing the brake pedal 43 while depressing the accelerator pedal 41. That is, the gear ratio RF
Becomes smaller and the load on the engine 1 becomes smaller. Therefore, the target engine speed ENG1 for the vehicle speed V at that time becomes higher than that when the brake pedal 43 is not depressed. As a result, the engine speed ENG required for the cargo handling operation can be obtained while the engine speed ENG required for running is secured, and thus smooth inching running is possible.

When the brake depression amount BRK is 70% or more, as described above, the gear ratio RF approaches zero at high speed regardless of the knob position, and the forklift is quickly decelerated. When the vehicle speed V enters a region where it becomes almost zero, that is, when the eccentricity amount δA is −β or more,
When β becomes less than or equal to β, the step motors 29A and 29B (substantially only the step motor 29A) are driven slowly this time. Therefore, the eccentric speed of the pintle 32 that returns to zero immediately before the stop of the forklift becomes slow, and the forklift is smoothly stopped.
Therefore, when the driver's rapid deceleration request causes the brake depression amount BRK to be 70% or more, the forklift is rapidly decelerated, and immediately before the stop, the vehicle speed V smoothly approaches zero. It will be stopped slowly. As a result, no shock is generated due to the sudden stop.

Next, the deceleration feeling control will be described. FIG. 23 is a flowchart showing the processing routine of the deceleration feeling control executed by the controller 61 in this embodiment. It should be noted that this processing routine is executed when the degree of deceleration is detected to be equal to or higher than a predetermined value while the vehicle is traveling.

First, in step 801, the knob position of the feeling adjustment knob 49 at that time is read based on the detection result from the knob sensor 50. In the next step 802, the rotational speeds SMA and SMB of both step motors 29A and 29B with respect to the knob position of the feeling adjusting knob 49 read in step 801 are calculated based on the map I.

In the following step 803, the rotation speeds SMA and SMB are set as the rotation speeds of both step motors 29A and 29B. Therefore, for example, when the vehicle is traveling in the above feedback control region, the position of the feeling adjusting knob 49 at that time is set to SOFT.
If it is, the step motors 29A and 29B are driven at the lowest speed (1 step / ST). Further, when the position of the feeling adjustment knob 49 at that time is HARD, the step motors 29A and 29B are set to the highest speed (1
Drive control is performed at 0 step / ST).

Next, at step 804, the accelerator opening degree ACC is read based on the detection result of the accelerator sensor 42. In the following step 805, the step 80
The accelerator opening ACC read in step 4 is zero, and the feeling adjustment knob 49 read in step 801.
It is determined whether or not the knob position of is HARD. Then, when the accelerator opening degree ACC is not zero or the knob position is not HARD, the subsequent processing is temporarily terminated. When the accelerator opening ACC is zero and the knob position is HARD, it is determined that there is a rapid deceleration request by the driver, the process proceeds to step 806, and the same process as step 609 described above is performed. That is, in step 806, the pintle position detection sensor 31A
Based on the detection result of, the eccentricity amount δA is −β or more, and
It is determined whether or not β or less. When it is determined that the eccentricity amount δA is −β or more and β or less,
The routine proceeds to the above-described stop routine. On the other hand, the amount of eccentricity δA
When it is determined that is greater than or equal to −β and less than or equal to β, the above operation is repeated until the eccentricity amount δA is greater than or equal to −β and less than or equal to β.

Then, in the stop routine, the processing described in the flowchart of FIG. 21 is executed, and the subsequent processing is temporarily terminated. As described above, in the deceleration control of the present embodiment, both the step motors 29A and 29 with respect to the position of the feeling adjusting knob 49 during deceleration.
The rotation speeds SMA and SMB of B are set. For this reason,
When decelerating by reducing the depression amount of the accelerator pedal while running in the feedback control region,
The position of the feeling adjustment knob 49 at that time is SOF.
If it is on the T side, the step motors 29A and 29B are driven at low speed, and if it is on the HARD side, the step motors 29A and 29B are driven at high speed. Therefore, by adjusting the feeling adjusting knob 49, it is possible to experience the deceleration feeling according to the driver's preference.

Further, in the case where the knob position is HARD and the accelerator pedal 41 is not depressed (the accelerator opening ACC is zero), it is assumed that there is a rapid deceleration request by the driver. As described above, the gear ratio RF (the eccentric amount δA of the pintle 32) approaches zero at high speed regardless of the position of the knob, and the forklift is quickly decelerated. Then, when the vehicle enters the region where the vehicle speed V becomes substantially zero, the eccentric speed at which the pintle 32 returns to zero becomes slow, and the forklift is smoothly stopped. Therefore, when the knob position is HARD and there is a rapid deceleration request from the driver that the accelerator pedal 41 is not depressed, the brake pedal 43 is set to 70%.
The forklift is rapidly decelerated as in the case of stepping on the vehicle, and the vehicle speed V smoothly approaches zero immediately before the forklift is stopped and is slowly stopped. As a result, no shock is generated due to the sudden stop.

As described above, in the region control for each condition of this embodiment, the condition is the first feedforward control region X.
When the forklift starts, the step motors 29A and 29B are driven and controlled at a low speed when the speed increase rate requested by the driver is relatively small. Therefore, at the start of traveling of the forklift, the forklift can be smoothly started if it is desired to travel at a very low speed. Further, since the gear ratio RF is feed-forward controlled on the basis of the map E, it is possible to quickly start and accelerate the vehicle without delaying the depression of the accelerator pedal 41, and it is possible to greatly improve the response.

When the condition is in the feedback control area Y, maximum axis output control is performed.
That is, in the maximum shaft output control, the target engine speed ENG1 calculated by the maximum shaft output control is the engine speed ENG controlled in the main control.
The gear ratio RF is changed so that the load is applied to the engine 1 to obtain the maximum shaft output STMAX. That is, since the engine speed ENG at that time is controlled by the feedback control so as to become the target engine speed ENG1, it is possible to obtain the maximum shaft output STMAX at the accelerator opening ACC at that time.

Further, in the feedback control area Y,
Since the upper limit is set, the gear ratio RF reaches the feedback control region Y after the start of traveling, and thereafter, the second ratio
Even if the vehicle enters the feedforward control region Z, the target gear ratio RF2 does not exceed the upper limit of the feedback control region. As a result, it is possible to prevent a rapid increase in the vehicle speed V against the driver's intention, and it is possible to further improve the operability of the forklift.

Further, in the inching control, when the inching running is performed, the accelerator pedal 41 is depressed and the brake pedal 43 is depressed, so that the target engine speed ENG for the vehicle speed V at that time is increased.
1 can be made higher than that when the brake pedal 43 is not depressed. As a result, the engine speed ENG required for traveling can be secured, and the engine speed ENG required for cargo handling work can also be obtained, so that inching traveling can be performed smoothly.

Further, in the deceleration feeling control, when the brake pedal 43 is depressed and the depression amount BRK is less than 70% during deceleration of the forklift, the position of the feeling adjustment knob 49 (SOFT) at that time is set. ~ HARD), the rotation speeds SMA and SMB of both step motors 29A and 29B are changed appropriately.

Therefore, the driver can decelerate according to the feeling that the driver sometimes demands, and the operability of the forklift at the time of deceleration can be further improved.

In the stop control according to the present invention, the accelerator opening degree ACC is zero when the brake depression amount BRK is 70% or more or when the knob operation position of the feeling adjusting knob 49 is HARD. When it becomes, it is assumed that there is a sudden stop request from the driver, and the rotation speeds SMA and SMB of the step motors 29A and 29B (substantially the step motor 29A
The rotational speed SMA of the pintle 32 is driven at the maximum speed, and the eccentricity amount δA of the pintle 32 is made to approach zero at high speed. Therefore, the forklift is quickly decelerated in response to the driver's request.

When the pintle 32 is eccentric at a high speed as described above and the eccentricity amount δA reaches near zero, the rotation speeds SMA and SMB of the step motors 29A and 29B (substantially the step The eccentric speed of the pintle 32 is lowered by driving the rotation speed SMA of the motor 29A only) at the minimum speed. Therefore, the degree of deceleration of the forklift is reduced immediately before stopping, and the forklift is smoothly stopped. As a result, as a result, the shock associated with the sudden stop does not occur, and the driver can experience a good stop feeling.

The present invention is not limited to the above embodiments, but may be configured as follows, for example, without departing from the spirit of the invention. (1) In the above embodiment, the pintles 32 and 14 of the hydraulic pump 3 and the hydraulic motor 4 are separately provided in the step motors 29A and 2A.
Although it is driven by 9B, the pintles 32, 14 may be driven by one step motor by a link mechanism (not shown).

(2) In the above embodiment, in addition to the engine speed control which is the main control, the area control for each condition including the maximum shaft output control, the inching control, the deceleration feeling control and the stop time control are performed. Although the configuration is adopted, the configuration may be such that only the main control and the stop control according to the present invention are performed, and it does not depart from the gist of the present invention even if other controls are not particularly executed.

(3) In the above embodiment, the feeling adjustment knob 49 is applied only during deceleration, but it may be applied during acceleration. (4) In the above embodiment, the pintle position sensors 31A, 3A
Although 1B is configured by a potentiometer, a rotary encoder that detects the amount of rotation of the step motors 29A and 29B is used instead of the potentiometer to output the output shaft 30 from the reference position.
A configuration may be adopted in which the eccentricity amounts δA and δB are calculated based on the rotation amount of.

(5) In the above embodiment, the brake depression amount B
When RK is 70% or more, the maximum speed is step motor 2
9A and 29B are set to be drive-controlled, but the numerical value is not particularly limited, for example, 50% or more or 8
You may change suitably, such as 0% or more.

(6) In the above embodiment, the throttle opening S
When the LO is less than “64step”, the step motor 29A is controlled to be driven at the lowest speed, but the throttle opening SLO at this time is not less than “64step”, for example, less than “20step” or “50step”.
You may change suitably, such as less than.

[0109]

As described above in detail, according to the stop control apparatus for an industrial vehicle equipped with the radial cylinder type variable displacement pump / motor of the present invention, when the driver makes a sudden stop request during traveling. , The pintle drive means is driven at a speed faster than when there is no stop request, and when the eccentric amount of the pintle is near zero,
Since the pintle drive means is driven at a speed slower than the previous drive speed, the vehicle can be stopped in response to the driver's prompt stop request, and moreover, a shock at the time of stop can be prevented, which is favorable. It has an excellent effect of being able to experience the feeling when stopped.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment embodying the present invention.

FIG. 2 is a cross-sectional view of the hydraulic motor taken along the moving direction of the pintle.

FIG. 3 is a cross-sectional view of the hydraulic motor taken along a plane orthogonal to the moving direction of the pintle.

FIG. 4 is a cross-sectional view of a state in which the hydraulic pump or the hydraulic motor is cut along a plane intersecting the output shaft.

FIG. 5 is a schematic perspective view of a pintle.

FIG. 6 is a diagram showing a relationship between an eccentric amount of a pintle of a hydraulic pump and a hydraulic motor and a vehicle speed.

FIG. 7 is a map in which a target throttle opening is set with respect to an accelerator opening.

FIG. 8 is a map in which the shaft output with respect to the engine speed is experimentally obtained.

FIG. 9 is a map in which a target engine speed with respect to an accelerator opening is set.

FIG. 10 is a map in which a feedback coefficient for a gear ratio is set.

FIG. 11 is a map in which each control region divided based on a throttle opening and a gear ratio is set.

FIG. 12 is a map in which a target gear ratio with respect to a throttle opening when executing the first feedforward region control is set.

FIG. 13 is a map in which a target gear ratio with respect to a throttle opening when executing the second feedforward region control is set.

FIG. 14 is a map in which a coefficient for multiplying a target gear ratio with respect to a brake depression amount is set.

FIG. 15 is a graph showing a target speed ratio newly set by multiplying a target speed ratio by a coefficient.

FIG. 16 is a map in which a motor rotation speed is set for a knob position.

FIG. 17 is an explanatory diagram illustrating a control flow.

FIG. 18 is a flowchart showing a processing operation during main control executed by the controller.

FIG. 19 is a flowchart showing the processing operation of region control for each condition, which is executed by the controller.

FIG. 20 is a flowchart showing a processing operation executed by a controller, wherein (a) shows a processing routine of feedforward area control, and (b) shows a processing routine of feedback area control (maximum axis output control). , (C) show other area control processing routines.

FIG. 21 is a flowchart showing a processing operation during inching travel control executed by a controller.

FIG. 22 is a flowchart showing the processing operation of a stop routine executed by the controller.

FIG. 23 is a flowchart showing a processing operation during deceleration feeling control executed by the controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Variable displacement pump / motor, 7 ... Drive wheel, 14, 32 ... Pintle, 22 ... Servo spool which comprises pintle drive means, 27 ... Control rod which comprises pintle drive means, 29A, 29B ... Pintle Step motors constituting drive means, 31A, 31B ...
Pintle position detection sensor as pintle eccentricity detection means, 41 ... Accelerator pedal, 42 ... Accelerator sensor as accelerator opening detection means, 51 ... Valve step motor as valve driving means, 61 ... Pintle drive control means, opening degree Calculation means, valve drive control means, controller as pintle drive speed control means and second pintle drive speed control means, RF ... Gear ratio, δA, δB ... Eccentricity.

Claims (1)

[Claims] 1. A radial cylinder type variable displacement pump / motor driven by an engine to drive driving wheels, and an eccentric amount of a pintle provided on the variable displacement pump / motor for controlling a gear ratio of a vehicle by displacement. A pintle drive means for changing the throttle valve opening degree, an accelerator opening degree detecting means for detecting an operation amount of an accelerator pedal operated to control an opening degree of a throttle valve, a valve driving means for opening and closing the throttle valve, and the accelerator. Target opening calculation means for calculating the target opening of the throttle valve based on the detection result of the opening detection means, and a valve for driving and controlling the valve driving means based on the target opening calculated by the target opening calculation means. Drive control means, and a pintle that drives and controls the pintle drive means based on the target opening calculated by the target opening calculation means. In an industrial vehicle provided with a radial cylinder type variable displacement pump / motor having a drive control means, when the driver makes a sudden stop request during traveling, the pintle drive means is faster than when the stop request is not made. The pintle driving speed control means for driving the And a second pintle drive speed control means for driving the pintle drive means at a speed slower than the drive speed by the drive speed control means. Stop control device.