JP2000304124A - Gear shift control device for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress shift shock, regardless of the size of a car body load, by controlling a solenoid proportional control valve according to the car body load so that engagement time from rising clutch hydraulic pressure to engaging completion of a clutch is roughly constant, after a gear shift determined based on a gear shift chart. SOLUTION: This device is provided with detection means such as a transmission output shaft rotational speed detecting device 18, a transmission input shaft rotational speed detecting device 17 and an accelerator opening detecting device 21. Output signals of the detection means are inputted into a transmission controller 40. In this controller 40, a gear shift stage is determined by a gear shift chart based on accelerator opening Ac and output speed No at first. In a solenoid valve signal output part 42, a solenoid valve 16 is made to output a solenoid valve signal Sp so that hydraulic pressure gradient of the clutch corresponding to the set speed stage may be set to a constant gradient value, even if car body load showing load to the clutch to be detected by a car body load detection means 51 is changed, and clutch hydraulic pressure is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shift control device for a work vehicle.

[0002]

2. Description of the Related Art A dump truck as a working vehicle is loaded with a heavy load and uses a transmission having multiple speeds to repeat starting, stopping, climbing up and downhill.
Since there are multiple stages, an automatic transmission control device is provided in consideration of the operability of the operator. A plurality of hydraulic clutches are provided inside the transmission, and the hydraulic pressure to each clutch is turned on and off, and the speed stage is set by the combination of the clutch that is applied and the clutch that is not applied . The transmission output shaft rotation speed for determining the start of the shift and the speed stage after the shift are determined by a shift diagram preset based on the accelerator opening and the transmission output shaft rotation speed, and the clutch of the corresponding speed stage is determined. A command is output to the electromagnetic proportional control valve that controls the hydraulic pressure to change the speed. FIG. 5 shows an example of a typical temporal change of the clutch oil pressure Pc in the automatic transmission control device for a work vehicle described above. The clutch engagement time at the time of maximum loading and at the time of empty load will be described. Assuming that the time t at the start of the shift is zero, and when the time t is zero, when the shift is determined, the hydraulic pressure (not shown) of the pre-shift clutch corresponding to the speed stage before the shift is set to zero. Further, oil is supplied to the post-shift clutch corresponding to the post-shift speed stage from the time point t at time t, and a filling time Tf is required until the clutch chamber is filled with oil. After the oil is filled, the clutch oil pressure rises at a predetermined gradient and increases to a predetermined maximum oil pressure Pm. Here, the predetermined gradient is considered at the time of maximum load, at the time of heavy load such as at the time of traveling on a steep road or at the time of mud,
The time until the post-shift clutch is engaged, ie, the time Tt during which the post-shift clutch is slipping, is determined to be within a range in which the durability of the clutch can be ensured, and a small shift shock is obtained.

[0003]

However, the predetermined gradient of the clutch oil pressure determined as described above has the following problems. Normally, when the vehicle load indicating the load on the clutch is small, such as when the vehicle is unloaded, the clutch is engaged with a small hydraulic pressure. For this reason, when the load on the vehicle body is small, the rising gradient of the clutch oil pressure is too large. Resulting in. Therefore, there is a problem that a change in rotation of the output shaft of the transmission per unit time is large, and a shift shock is large. Further, there is also a problem in that the shifting completion time is not constant due to load fluctuations such as the weight of the load and the gradient of the traveling road, so that shifting operability is not good.

The present invention has been made in view of the above-mentioned problems, and has a small shifting shock and a substantially constant shifting time, and has a good shifting operability with a substantially constant shifting irrespective of the size of the vehicle body load. It is an object of the present invention to provide a shift control device for a vehicle.

[0005]

Means for Solving the Problems, Functions and Effects In order to achieve the above-mentioned object, the invention according to the first aspect of the present invention relates to a speed stage by engaging and disengaging a plurality of hydraulic clutches and combining a plurality of gears. A transmission that shifts according to
An accelerator opening detector that detects the amount of accelerator operation by the operator as an accelerator opening, a transmission output shaft rotation speed detector that detects the output shaft rotation speed of the transmission, and a predetermined hydraulic pressure clutch according to the speed stage of the transmission. An electromagnetic proportional control valve that supplies hydraulic pressure, and a speed stage is determined based on a shift diagram that is set based on an accelerator opening and a transmission output shaft rotation speed, and a constant gradient value corresponding to the determined speed stage is determined. A shift control device for a work vehicle, comprising: a speed stage determining unit that outputs a command signal of a clutch hydraulic pressure rising gradient; and a transmission controller having an electromagnetic valve signal output unit that inputs the command signal and drives an electromagnetic proportional control valve. , An engine output torque calculator that calculates an engine output torque based on an accelerator opening Provided, the transmission controller detects the vehicle load, as engagement time until engagement is complete standing up clutch hydraulic pressure of the post-shift clutch which is determined based on the shift map is substantially constant,
A command signal output to the electromagnetic proportional control valve is set in accordance with the detected vehicle load to set a clutch oil pressure rising gradient, and a command signal based on the set gradient is subjected to electromagnetic proportional control via an electromagnetic valve signal output unit. It is configured to include a modulation control unit that outputs to a valve.

According to the invention described in the first aspect, even when the vehicle body load fluctuates, the clutch oil pressure rising gradient set so that the engagement time is substantially constant according to the magnitude of the vehicle body load. Since the hydraulic pressure rises, the clutch always engages for the same engagement time. Thus, even when the vehicle body load is small, the clutch is not engaged in a short time, so that it is possible to obtain a shift control device with a small shift shock regardless of the magnitude of the vehicle body load.

According to a second aspect of the invention, based on the first aspect, a transmission input shaft rotation speed detector for detecting an input shaft rotation speed of the transmission is additionally provided, and the modulation control unit further includes: While the hydraulic pressure of the corresponding clutch is being started, when the absolute value of the difference between the transmission input shaft rotation speed and the input shaft conversion rotation speed in the post-shift speed stage of the transmission output shaft rotation speed becomes smaller than a predetermined threshold value, the clutch A command to change the hydraulic pressure rising gradient to a predetermined gradient that is larger than the rising gradient set at the start of gear shifting is output to the electromagnetic proportional control valve via the electromagnetic valve signal output unit.

According to the invention described in the second aspect, the absolute value of the difference between the transmission input shaft rotation speed and the input shaft conversion rotation speed in the post-shift speed stage of the transmission output shaft rotation speed is set to a predetermined input shaft conversion relative speed threshold value. If it is determined that the gradient is smaller, it is considered that the engagement of the clutch has been completed, the gradient that has been set so far is changed to a predetermined gradient with a greater gradient, and the clutch hydraulic pressure is rapidly increased,
When the clutch oil pressure reaches a predetermined maximum oil pressure, the shift is completely completed. The time from when the clutch is completely engaged to when the predetermined maximum oil pressure is reached is substantially equal regardless of the magnitude of the vehicle body load, since the predetermined oil pressure rise gradient is sufficiently large. Normally, the time required for filling the clutch chamber with the oil from the start of the shift until the clutch oil pressure starts to rise is substantially equal for each clutch. Further, according to the first aspect, the time from the start of the clutch oil pressure rise to the completion of the engagement of the clutch is substantially equal, so that the time from the start of the shift to the completion of the shift is substantially equal, and therefore, regardless of the magnitude of the vehicle body load. Approximately constant shifting time is always obtained. For this reason, it is possible to obtain a shift control device with a good operation feeling.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of the hardware configuration. A transmission 12 for selecting a speed stage by connecting or releasing a plurality of clutches (not shown) by turning on and off clutch hydraulic pressure is mounted on an output shaft 23 of the engine 11 via a torque converter 13. A rear wheel 22, which is a drive wheel, is mounted on an output shaft of the transmission 12 via a speed reducer (not shown) after the transmission. At a predetermined position of the transmission 12, a plurality of electromagnetic proportional control valves 16 (hereinafter referred to collectively as electromagnetic proportional control valves for each clutch) for supplying a predetermined hydraulic pressure to the plurality of clutches for selecting each speed stage, respectively. Call it)
Is attached. An accelerator pedal 20 operated by the operator is provided at the feet of the operator.

As a detector, a transmission output shaft rotation speed detector 18 (hereinafter, referred to as output speed detector 18) for measuring a transmission output shaft rotation speed No (hereinafter, referred to as output speed No) is a transmission output shaft. It is attached near the periphery. A transmission input shaft rotation speed detector 17 (hereinafter, referred to as input speed detector 17) for measuring a transmission input shaft rotation speed Ni (hereinafter, referred to as input speed Ni) is attached near the periphery of the transmission input shaft. ing. An accelerator pedal operation amount (hereinafter, referred to as an accelerator pedal operation amount) is provided below the accelerator pedal 20.
An accelerator opening detector 21 for detecting the accelerator opening Ac) is provided.

As a controller, a transmission controller 40 and an engine controller 60 for controlling a fuel injection amount are provided. The transmission controller 40 has a speed stage determination unit 41, an electromagnetic valve signal output unit 42, and a modulation control unit 50. Here, the speed gear determining unit 41 determines a speed gear based on a shift diagram based on the accelerator opening Ac and the output speed No. The electromagnetic valve signal output unit 42 outputs the electromagnetic valve signal Sp for setting the hydraulic pressure gradient of the clutch corresponding to the set speed stage to a constant gradient value even when the vehicle load indicating the load on the clutch changes. Output to The modulation control unit 50 controls the rising gradient and the rising timing of the clutch oil pressure according to the vehicle body load. Signals of the accelerator opening Ac and the output speed No are input to the speed gear determination unit 41 via an input circuit (not shown). From the speed gear determining unit 41, a shift start signal Si that is set to “1” when the speed gear is determined, and set to “0” when the speed gear is not determined,
The pre-shift speed reduction gear ratio data ρ is output to the modulation control unit 50. The solenoid valve signal output unit 42 includes:
A command from the modulation control unit 50 to set the clutch oil pressure gradient M representing the temporal gradient of the clutch oil pressure, a command to set the pre-shift clutch oil pressure Pn corresponding to the clutch to be released before the shift to zero, and an engagement after the shift A hydraulic pressure command Cp including a command to raise the post-shift clutch hydraulic pressure Pa corresponding to the clutch to be performed is input. Also,
From the electromagnetic valve signal output unit 42, an electromagnetic valve signal Sp for controlling each clutch hydraulic pressure is output to the electromagnetic valve 16 via an output drive unit (not shown).

The modulation control section 50 has a vehicle body load detecting means 51 for detecting a vehicle body load, and a gradient storage means 52 for storing a plurality of data of the clutch hydraulic gradient M. Each data of the small gradient Ms and the large gradient Mb set at the time of starting the clutch engagement is stored in the gradient storage 52.
Data of the engagement determination gradient Mm set before the clutch oil pressure reaches a predetermined maximum oil pressure Pm after the clutch engagement is completed is stored in advance. Here, the small gradient Ms is set when the vehicle load is small, and is set to a smaller gradient value than the large gradient Mb set when the vehicle load is large. Further, the engagement determination gradient Mm for obtaining a hydraulic pressure for firmly engaging the clutch is a gradient having a larger value than the large gradient Mb. The modulation control unit 50 includes:
The input speed Ni, the output speed No, the shift start signal Si, and the pre-shift speed gear reduction ratio ρ data are input via an input circuit (not shown). Further, the modulation control unit 50 receives an engine output torque To value from the engine controller 60. The modulation control unit 50 outputs the hydraulic pressure command Cp to the solenoid valve signal output unit 42.
Output to

An engine controller 60 calculates an engine output torque based on the accelerator opening Ac, an engine output torque calculator 61, and a fuel injection amount calculator 62 calculates a fuel injection amount command value for the fuel injection device 19. have. The accelerator opening Ac is input to the engine output torque calculator 61. Further, the calculated engine output torque To value is output from the engine output torque calculation section 61 to the modulation control section 50. The accelerator opening Ac is input to the fuel injection amount calculation unit 62, and the fuel injection amount signal Fi is output from the fuel injection amount calculation unit 62 to the fuel injection device 19 via an output drive unit (not shown). Have been.

FIG. 2 shows a control flowchart of the modulation control unit 50. FIG. 3 shows the pre-shift clutch oil pressure Pn and the post-shift clutch oil pressure Pn when the vehicle body load is small.
a, a transmission speed input / output relative rotational speed Nr (hereinafter referred to as input shaft converted relative speed Nr), which is a difference between the input shaft rotational speed of the transmission input shaft and the input shaft converted rotational speed in the post-shift speed stage of the transmission output shaft rotational speed. ) Are shown over time. FIG.
FIG. 3 shows a temporal change of the same state quantity as in FIG. 3 when the vehicle body load is large. The control processing procedure of the present embodiment will be described with reference to these drawings. In the description of FIG. 2, each processing step number is represented by adding S. Before the shift, the clutch oil pressure Pn before the shift is set to a predetermined maximum oil pressure Pm, and the clutch oil pressure Pa after the shift is set to a zero value (S21). Next, the shift determination signal Si determined and output by the speed gear determination section 41 is output.
Is determined as "1" or "0" (S22). If the shift determination signal Si is "0", the process returns to S21.
If it is "1", the time t at this time is set to zero, and the running resistance inclusion load W representing the vehicle body load is calculated by the vehicle body load detecting means 51 by the equation (1) based on the output speed No and the engine output torque To ( S23). Here, the running resistance inclusion load W includes not only the vehicle weight including the loaded load but also the running resistance such as the component force in the direction of the traction force of the vehicle weight due to the slope of the running road and the frictional resistance of the running road surface. Value. W = K × g × To / (d (No) / dt) (1) where d (No) / dt: temporal derivative of output speed No. K: conversion coefficient g : Gravitational acceleration The conversion coefficient K includes the reduction ratio of the transmission before the shift speed, the reduction ratio after the transmission, and the tire radius.

A load threshold W having a running resistance containing load W having a value that is a predetermined multiple (for example, 1.5 times) of the vehicle weight Wk in an unloaded state.
It is determined whether it is smaller than j (S24). Load threshold W
j or more, a large gradient Mb is set as shown in FIG. 4 as a clutch hydraulic gradient M representing a temporal gradient at the time of the rise of the clutch hydraulic pressure, and a small gradient Ms as shown in FIG. Is selected from the gradient storage means 52 and set (S25, S26). Here, when the vehicle body load is large, that is, when the vehicle body inertia is large, the value of the large gradient Mb does not impair the clutch durability even if the clutch heating value exceeds a predetermined heating value, and a small shift shock occurs. It is set in advance to the obtained value. In addition, small gradient Ms
Is substantially equal to the time Tb from when the clutch oil pressure starts to rise and the engagement is completed when the vehicle body load is small and when the clutch oil pressure starts to rise and the engagement is completed when the vehicle body load is large, In addition, it is set in advance to a value at which a small shift shock can be obtained. The hydraulic pressure command Cp including the set clutch hydraulic pressure gradient M, the command to set the pre-shift clutch hydraulic pressure Pn to a zero value, and the command to raise the post-shift clutch hydraulic pressure Pa is a clutch hydraulic pressure having a constant gradient value. The command is output to each solenoid valve 16 via the solenoid valve signal output unit 42 (S2
7). As a result, the pre-shift clutch oil pressure Pn becomes zero, and oil starts to be supplied to the clutch chamber of the post-shift clutch. After the shift, oil is supplied to the clutch chamber of the clutch, and the filling time required for filling (Tfs in FIG. 3, FIG.
After the elapse of Tfb), the hydraulic pressure becomes the predetermined gradient Ms, M
Stand up at b. Since the filling time of each post-shift clutch is substantially equal, the filling time Tfs when the vehicle load is small is substantially equal to the filling time Tfb when the vehicle load is large.

Next, an input shaft converted relative speed Nr represented by the following equation (2) is calculated (S28), and its absolute value is determined by a predetermined post-shift speed transmission input / output relative rotational speed threshold dNr (hereinafter, threshold dNr). Is determined (S29). Nr = Ni−ρ × No (2) If the value is equal to or greater than the threshold value dNr, the flow returns to S28 to calculate the input shaft converted relative speed Nr again, and repeat the above processing. If it is smaller, it is determined that the clutch has completed the engagement, and then the clutch hydraulic pressure gradient M is set to the determined engagement gradient Mm selected from the gradient storage means 52 (S30). The time at which it is determined that the clutch has completed the engagement is referred to as a small load engagement completion time Ts when the vehicle load is small, and a large load engagement completion time Tb when the vehicle load is large. The time from the rise of the clutch oil pressure after completion of the filling of the clutch chamber with oil until the completion time Ts at the time of small load engagement or the time Tb at the time of large load engagement completion is referred to as an engagement time. The clutch hydraulic pressure gradient M changed to the engagement determination gradient Mm is replaced with a clutch hydraulic pressure command having a constant gradient value as a hydraulic pressure command Cp, and is output to each of the solenoid valves 16 via the solenoid valve signal output unit 42. The clutch oil pressure reaches a predetermined maximum oil pressure Pm at the engagement determined gradient Mm, and the shift is completed. The time when the shift is completely completed is set as a low-load shift completion time Tes and a large-load shift completion time Teb, respectively, corresponding to a small load and a large load. Engagement for increasing the clutch oil pressure to secure the engagement between the time when the clutch oil pressure gradient M becomes the engagement determination gradient Mm and the time when the light load shift is completed and the time when the heavy load shift is completed or Teb. It is called a fixed time.

According to this embodiment, the running resistance inclusion load W
Is smaller than the load threshold Wj, the gradient is a small gradient Ms.
To set the clutch hydraulic pressure. The small gradient Ms is set so that the engagement time from when the clutch oil pressure starts to rise and the engagement is completed when the vehicle body load is small is substantially equal to the engagement time due to the large gradient Mb when the vehicle body load is large. It is set in advance so that a shift shock can be obtained. As a result, the clutch is engaged with a constantly small shift shock regardless of the magnitude of the vehicle body load.

The time from when the clutch oil pressure rises to when the clutch is engaged, that is, the engagement time (between Tfs-Ts or Tfb-
Tb) is substantially the same regardless of the magnitude of the vehicle load. Also, the filling time Tfs or Tfb required until the clutch chamber of the post-shift clutch is filled with oil before the clutch oil pressure rises is substantially equal in each post-shift clutch. Therefore, the total time of the filling time and the engagement time is substantially equal regardless of the magnitude of the vehicle body load. Since the engagement determination gradient Mm set as the gradient after the absolute value of the input shaft converted relative speed Nr becomes smaller than the threshold value dNr is a sufficiently large gradient, the engagement determination times are substantially equal regardless of the magnitude of the vehicle body load. Become. Thus, regardless of the magnitude of the vehicle body load, the engagement time from the start of the shift until the engagement is completed can be controlled to be substantially equal, and the predetermined maximum hydraulic pressure P after the engagement is completed.
Since the engagement determination time to reach m is also substantially equal, a substantially constant shift time is always obtained as a whole.

In the present embodiment, the vehicle body load is classified into two types, large and small, and the rising gradient of the clutch oil pressure is set for each of the two types. And a clutch rising gradient may be set for each. Alternatively, a calculation formula for obtaining the hydraulic gradient M according to the magnitude of the vehicle body load may be set from the experimental data, and the calculation may be performed using this calculation formula. In this embodiment,
Although the acceleration of the vehicle body is calculated by differentiating the rotational speed of the transmission output shaft with respect to time, a value detected by an accelerometer attached to a predetermined position in the front-rear direction of the vehicle body may be used. Although the running resistance inclusion load is calculated from the engine output shaft torque and the vehicle acceleration, the vehicle weight may be directly measured by other means capable of measuring the weight, such as the fluid pressure of a hydropneumatic suspension. Absent. Furthermore, in the present embodiment, the load threshold Wj is set to the formula “1.5 × unloaded vehicle weight Wk” in order to roughly classify the vehicle load into two, large and small. May be set to the load threshold value Wj which is easily distinguishable from the load threshold value Wj.

As described above, according to the present invention, the clutch is engaged by the clutch oil pressure gradient according to the magnitude of the vehicle body load. As a result, the clutch engagement time can be made substantially equal regardless of the magnitude of the vehicle body load, and the shift shock can be further reduced. At the same time when the engagement is completed, the clutch hydraulic pressure is raised at the engagement determination gradient having a predetermined large gradient value.
Thus, the time from the completion of the engagement to the completion of the shift can be set to be the shortest and substantially equal regardless of the magnitude of the vehicle body load. Thus, regardless of the magnitude of the vehicle body load, the shift shock is small, the shortest and substantially constant shift required time can be obtained, and a shift control device with good operability can be obtained.

The present invention has the following effects. At the same time as the clutch engagement is almost completed, the clutch oil pressure is set to the fixed engagement gradient to reach the predetermined clutch maximum pressure, so that firm engagement that does not slip even when the engine maximum torque passes through the engagement clutch is quick. Is obtained. For this reason, it is possible to obtain a shift control device having a good response feeling of acceleration according to the opening degree of the engine accelerator. Furthermore, since the magnitude of the vehicle body load can be easily determined using the load including the running resistance, an inexpensive and practical shift control device can be obtained.

[Brief description of the drawings]

FIG. 1 is a hardware configuration diagram according to the present invention.

FIG. 2 is a flowchart of a modulation control unit.

FIG. 3 is a diagram illustrating a temporal change of a clutch hydraulic pressure before a shift, a clutch hydraulic pressure after a shift, and an input shaft converted relative speed when a vehicle body load is small, and illustrates a change in a clutch hydraulic pressure gradient.

FIG. 4 is a diagram illustrating a temporal change of a clutch oil pressure before a shift, a clutch oil pressure after a shift, and an input shaft converted relative speed when a vehicle body load is large, and illustrates a change in a clutch oil pressure gradient.

FIG. 5 is a diagram illustrating engagement completion times when a vehicle body load is large and when the vehicle body load is small, based on a typical example of a clutch hydraulic pressure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Transmission, 13 ... Torque converter, 16 ... Electromagnetic proportional control valve, 17 ... Transmission input shaft rotation speed detector, 18 ... Transmission output shaft rotation speed detector, 19 ... Fuel injection device,
20: accelerator pedal, 21: accelerator opening detector, 2
2 ... rear wheel, 23 ... engine output shaft, 40 ... transmission controller, 41 ... speed stage determination unit, 42 ... solenoid valve signal output unit, 50 ... modulation control unit, 51 ...
Vehicle body load detecting means, 52 ... gradient storage means, 60 ... engine controller, 61 ... engine output torque calculating section, 6
2: Fuel injection amount calculation unit, Ni: Transmission input shaft rotation speed, No: Transmission output shaft rotation speed, Sp: Solenoid valve signal, Ac: Accelerator opening, Si: Shift determination signal, ρ: Shift speed reduction ratio before shift , Cp: oil pressure command, To: engine output torque.

Claims (2)

[Claims] A transmission that shifts in accordance with a speed stage by engaging and disengaging a plurality of hydraulic clutches and a plurality of gears; and an accelerator opening detector that detects an operation amount of an accelerator by an operator as an accelerator opening. A transmission output shaft rotation speed detector that detects the transmission output shaft rotation speed; an electromagnetic proportional control valve that supplies a predetermined oil pressure to each hydraulic clutch according to the speed stage of the transmission; an accelerator opening and transmission output shaft rotation A speed stage determining unit that determines a speed stage based on a shift diagram set based on the speed, and outputs a command signal of a clutch oil pressure rising gradient having a constant gradient value corresponding to the determined speed stage; and a command signal. Transmission having an electromagnetic valve signal output section for driving an electromagnetic proportional control valve by inputting A transmission control device that calculates an engine output torque based on an accelerator opening, a transmission controller detects a vehicle body load, and controls a speed shift determining unit. An electromagnetic proportional control valve according to the magnitude of the detected vehicle body load so that the engagement time from when the clutch oil pressure of the clutch determined after the shift is raised based on the diagram until the engagement is completed is substantially constant. A modulation control unit that sets a clutch oil pressure rising gradient of a command signal to be output to the electromagnetic proportional control valve through an electromagnetic valve signal output unit, and sets a command signal based on the set gradient. Transmission control device for work vehicle. 2. The transmission control device for a work vehicle according to claim 1, further comprising a transmission input shaft rotation speed detector for detecting an input shaft rotation speed of the transmission, wherein the modulation control unit further corresponds to the post-gear speed stage. When the absolute value of the difference between the transmission input shaft rotation speed and the input shaft converted rotation speed in the post-shift speed stage of the transmission output shaft rotation speed becomes smaller than a predetermined threshold while the clutch hydraulic pressure is being A command to change the rising gradient of the vehicle to a predetermined gradient that is greater than the rising gradient set at the start of the shift, to the electromagnetic proportional control valve via an electromagnetic valve signal output unit. Control device.