JPH0728442Y2 - Transmission for industrial vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a transmission for an industrial vehicle such as a forklift, and particularly to a gearshift having two forward and two reverse gears, which is useful for small industrial vehicles. Regarding the device.

(Prior Art) In recent years, in order to provide a large driving force, improve traveling performance, and improve work efficiency, even in industrial vehicles such as relatively small forklifts, a multi-stage transmission having two forward gears and two reverse gears Is being adopted.

By the way, in the case of the conventional transmission for two forward gears and two reverse gears for an industrial vehicle, as shown in FIG. 10, between the _two counter shafts S ₂ and S ₂ ′ and between the _two counter shafts S ₂ . ₂ , S ₂ ′ and the output shaft (in this specification, the output shaft is simply referred to as the output shaft of the transmission) S ₃ between the forward first speed and the second speed
Fast, reverse First clutch, second clutch C _FL , C _FH , C _RL , C
Disposed of _RH, four clutches C _FL upon formation of each shift speed, C _FH, C _RL, by operating appropriately via one or two control apparatus or the like of the _RH C, forward It realized two-speed reverse and two-speed shift.

However, when four clutches are arranged between the shafts in this way, the price becomes expensive, the mechanical structure becomes complicated, and the number of control targets for controlling these clutches becomes four. The control device was also complicated.

Under such circumstances, the applicant of the present invention, as shown in FIG. 11, has the clutches C _H , C _F , C _R for high speed switching, forward and reverse, and one free clutch between each shaft. Inventing a transmission with two forward gears and two reverse gears, which is configured by arranging the wheels F, the transmission gear for an industrial vehicle is cheaper in price and structurally simpler than the conventional one. (Japanese Patent Application No. 2-16447).

This industrial vehicle transmission, as shown in FIG. 11,
Input shaft S ₁ to which rotation from the engine output shaft S _e side is transmitted
The gear G ₁ for low speed is fixed on the top, and the gear G ₂ for high speed is discontinuously arranged via the clutch C _H for high speed switching.
On the counter shaft S ₂ parallel to the input shaft, a gear G ₃ meshing with the gear G ₁ is arranged via a free wheel F that transmits rotation only from the input shaft side to the counter shaft S ₂ side. There is. Further, on the counter shaft S ₂ is fixedly mounted a gear G _4, which meshes with the gear G _2, as well as providing the gear G ₅ and via the clutch C _F intermittent freely for forward intermittently freely The gear G ₆ was arranged via the reverse clutch C _R. Then, on the output shaft S ₃ parallel to the input shaft S ₁ and the counter shaft S ₂ , the gear G ₇ meshed with the gear G ₅ and the gear G ₆
The gears G ₈ meshing with each other via G ₉ were fixed.

Then, the industrial vehicle transmission thus configured,
By operating the clutches C _H , C _F , C _R when shifting,
It is possible to obtain two forward gears and two reverse gears as follows. That is, in order to obtain the forward first speed (low speed stage), the high speed switching clutch C _H is turned off, the forward drive clutch C _F is turned on, and the reverse drive clutch C _R is turned off. Axis S _e
Rotation from the side is transmitted through the freewheeling F provided with the gear G ₃ which meshes from the input shaft S ₁ gear G ₁ and to the counter shaft S _2, the counter shaft S _2, the output gear G ₅ It can be transmitted to the output shaft S ₃ via the forward clutch C _F provided on the side and the gear G ₇ meshing with the gear G ₅ .

To obtain the second forward speed (high speed), turn on the high speed switching clutch C _H , turn on the forward clutch C _F, and turn off the reverse clutch C _R rotation from the shaft S _e side is transmitted via the gear G ₄ which meshes from the input shaft S ₁ to the clutch C _H and a gear G ₂ provided with the gear G ₂ to the counter shaft S _2, the counter shaft S _2, It is possible to transmit to the output shaft S ₃ via the forward clutch C _F having the gear G ₅ on the output side and the gear G ₇ meshing with the gear G ₅ . In this case, the freewheel F spins idle (is rotatable) because it can be rotated faster through the high speed switching clutch C _H. On the other hand, in order to obtain the first reverse speed (low speed), the high speed switching clutch C _H is turned OFF and the forward clutch C _{F is}
The OFF, if the clutch C _R for reverse to ON, the rotation of the output shaft S _e side of the engine, the freewheeling F provided with the gear G ₃ which meshes from the input shaft S ₁ gear G ₁ and to this Through the counter shaft S ₂ and from this counter shaft S ₂ to the gear G ₆
Reverse clutch C _R equipped with an output side and this gear G ₆
It can be transmitted to the output shaft S ₃ via the gear G ₉ and the gear G ₈ meshing with the gear.

To obtain the second reverse speed (high speed), turn on the high-speed switching clutch C _H , turn the forward clutch C _F OFF, and turn the reverse clutch C _R ON to output the engine rotation from the shaft S _e side is transmitted via the gear G ₄ which meshes from the input shaft S ₁ to the clutch C _H and a gear G ₂ provided with the gear G ₂ to the counter shaft S _2, from the counter shaft S ₂ , A reverse clutch C _R having a gear G ₆ on the output side and a gear G ₉ meshing with the gear G ₆
And can be transmitted to the output shaft S ₃ via the gear G ₈ .
In this case, the freewheel F spins idle (is rotatable) because it can be rotated faster through the high speed switching clutch C _H.

In this way, with three clutches and one freewheel, and by only controlling (operating) three clutches, it is possible to use the conventional four clutches to obtain the two forward and two reverse shifts. Capable of performing the action of
Moreover, an industrial vehicle transmission having a simple structure is provided.

(Problems to be solved by the invention) However, in the case of the transmission shown in FIG. 10 or FIG. 11, the forward and reverse clutches C _F , C are used.
_{Since two Rs} (or C _FL , C _FH , C _RL , C _RH ) are arranged in series in the longitudinal direction of the transmission, the dimension of the transmission in the axial longitudinal direction becomes long, and the size is small. In the case of a vehicle such as a forklift truck having a short front-rear axis distance, it cannot be mounted.

Further, even if it can be mounted, there is an inconvenience that the space for arranging other constituent devices has to be considerably narrowed.

The present invention has been made in view of the above-mentioned current situation, and has two forward and two reverse stages, which is configured only by three clutches and one free wheel and is configured as short as possible in the axial direction of the transmission. An object of the present invention is to provide a transmission device for a multi-stage industrial vehicle.

(Means for Solving the Problems) In a transmission for an industrial vehicle according to the present invention, a gear train for high speed has an input shaft and a counter shaft of the transmission so that power is selectively transmitted at a high speed stage or a low speed stage. fast switching is disposed through a clutch C _H of changeover, transmission gear train for a low speed, a rotation only to the counter shaft side from the input shaft between the input shaft and the counter shaft of the transmission between the At least two gear trains for transmitting the rotational force from the counter shaft to the output shaft through the forward clutch C _F and the reverse clutch C _R , respectively. A transmission device for an industrial vehicle, which is separately provided between a counter shaft and an output shaft, and is configured to be capable of performing two forward gear shifts and two reverse gear shifts with the above three clutches and one free wheel. Transmission of torque from shaft Downstream of the counter shaft in a second counter shaft and the output shaft are disposed parallel to the input shaft and the counter shaft via the clutch C _F for forward between the output shaft and the counter shaft A forward gear train is provided, and a reverse clutch C _{R is provided} between the counter shaft and the second counter shaft.
And a gear train for meshing with each other for transmitting the rotational force for the reverse travel is fixedly provided on each of the second counter shaft and the output shaft. , A clutch C _H for high speed switching arranged on either the input shaft or the counter shaft, and a forward clutch C _F arranged on either the counter shaft or the output shaft and a counter shaft or a second counter shaft And the reverse clutch C _R disposed in any one of the above-mentioned positions are separately disposed on any one of the shafts and located in the same plane orthogonal to the longitudinal direction of the shaft of the transmission. And

The terms "for forward travel" and "for reverse travel" referred to in the claims for utility model registration are the names when the transmission is mounted on a specific vehicle body, and the forward and reverse directions of the vehicle body are reversed. If the setting is set to "Forward", the name is opposite to "Forward", and also when the direction of rotation transmitted to the input shaft of the transmission is reversed, the "Forward", "Forward" It goes without saying that the name is opposite to that for "reverse." As described above, the designations "for forward drive" and "for reverse drive" are based only on the usage of the transmission, and do not determine the structural characteristics of the transmission (action). The transmission for an industrial vehicle configured in Fig. 3 has three clutches C _H , C _F , C _{R in} the same plane at right angles to the longitudinal direction of the transmission, so Can be the shortest.

Then, this transmission for an industrial vehicle uses the 11th
By operating the clutches C _H , C _F , and C _R in the same manner as in the transmission shown in the figure, it is possible to obtain a two-speed forward and two-reverse speed change as follows.

That is, (a). When the high speed switching clutch C _H is turned off, the forward driving clutch C _F is turned on, and the reverse driving clutch C _R is turned off, the rotation is transmitted to the counter shaft through the freewheel F by the low speed gear train. The rotation is transmitted from the counter shaft to the output shaft via the forward clutch C _F, and the first forward speed (low speed stage) is obtained.

Also, (b). If the clutch C _H for high speed switching is turned ON, the clutch C _F for forward driving is turned ON, and the clutch C _R for reverse driving is turned OFF, the counter shaft is connected to the counter shaft by the gear train for high speed via the clutch C _H for high speed switching. The rotation is transmitted, and the rotation is transmitted from the counter shaft to the output shaft via the forward clutch C _F to obtain the second forward speed (high speed stage). Then, in this case, since the high speed switching clutch C _H can be rotated more quickly, the free wheel F idles (is rotatable).

On the other hand, (c). When the high speed switching clutch C _H is turned off, the forward drive clutch C _F is turned off, and the reverse drive clutch C _R is turned on, the rotation is transmitted to the counter shaft by the gear train through the free wheel F, and this counter is transmitted. The rotation is transmitted from the shaft to the second counter shaft via the reverse clutch C _R, and
The rotation is transmitted from the counter shaft of the
High speed (low speed) can be obtained.

Also, (d). When the high speed switching clutch C _H is turned on, the forward driving clutch C _F is turned off, and the reverse driving clutch C _R is turned on, rotation is transmitted to the counter shaft by the gear train via the high speed switching clutch C _H. Then, the rotation is transmitted from this counter shaft to the second counter shaft through the reverse clutch C _R , and further the rotation is transmitted from the second counter shaft to the output shaft, and the second reverse speed (high speed stage) Is obtained. In this case, the freewheel F spins idle (is rotatable) because it can be rotated faster through the high speed switching clutch C _H.

The operation status of each clutch and the free wheel at each shift stage described above is summarized in FIG.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a skeleton diagram showing the structure of a torque converter type forward two-stage reverse two-stage automatic transmission according to the present invention, and FIG. 4 is a clutch for forming each forward two-stage reverse two-stage shift stage. FIG. 5 is a hydraulic circuit diagram for actuating each clutch of the transmission shown in FIG. 1, and FIG. 5 is a table showing the operating condition of the freewheel.

In FIG. 1, S ₁ is an input shaft, S ₂ is a counter shaft, S ₂ ′ is a second counter shaft, S ₃ is an output shaft of the transmission, and these shafts S ₁ , S ₂ , S ₂ ′, S ₃ are arranged in parallel with each other.

In the present embodiment, the input shaft S ₁ is configured integrally with the shaft S _T connected to the turbine side of the torque converter T,
The pump side of the torque converter T is connected to an output shaft S _{e of the} engine (not shown).

In this embodiment, gears G ₁ and G ₂ are fixedly mounted on the input shaft S ₁ .

The aforementioned counter shaft S _2, the gear G ₁ and the gear G ₃ which meshes, via a drivable free feel F from the input shaft S ₁ to the counter shaft S ₂ side, it is disposed. Further, a gear G ₄ meshing with the gear G ₂ is discontinuously arranged on the counter shaft S ₂ via a clutch C _H for high speed switching, and the clutch C _H for high speed switching is turned on. When, the above gear G ₄
Is fixed to the counter shaft S ₂ and the clutch C _H is OFF, the gear G ₄ is rotatable with respect to the counter shaft S ₂ . Therefore, the above freewheel F has the input shaft S ₁
Between the counter shaft S ₂ and the counter shaft S ₂ only when the rotation speed due to the meshing path between the gears G ₁ and G ₃ is higher (greater) than the rotation speed due to the meshing path between the gears G ₂ and G ₄ equipped with the clutch C _H. ,
Functions to transmit rotation from the input shaft S ₁ to the counter shaft S ₂ .

Further, a gear G ₅ is fixedly mounted on the counter shaft S ₂ .

Then, the second counter shaft S ₂ 'on the opposite side of the output shaft S ₃ separates the counter shaft S _2, said counter shaft S ₂
A gear G ₆ that meshes with the upper gear G ₅ is discontinuously disposed with respect to the second counter shaft S ₂ ′ via a reverse clutch C _R, and the second counter shaft S _A gear G ₇ is fixedly attached to ₂ ′.

Therefore, the reverse clutch C _R is the clutch latch C _R
There gear G ₆ is provided therein when the ON is 'fixed to the, from the counter shaft S ₂ the second counter shaft S _2' The second counter shaft S ₂ rotates in is transmitted, whereas when the OFF is The gear G ₆ provided there is rotatable with respect to the second counter shaft S ₂ ′.

Then, the output shaft S ₃ is provided with the gear G _{5 of the} counter shaft S _2.
A gear G ₈ meshed with the gear G ₇ on the _second counter shaft S ₂ ′ is provided so as to be discontinuous with respect to the output shaft S ₃ via a forward clutch C _F. The meshing gear G ₉ is fixed.

Therefore, the clutch C _F for forward the gear G ₈ which is provided therein when the clutch C _F is ON is secured to the output shaft S _3, rotation is transmitted from the counter shaft S ₂ to the output shaft S ₃ Is
On the other hand, when it is OFF, the gear G ₈ is rotatable with respect to the output shaft S ₃ .

Further, in the case of the transmission according to the present invention, the clutches C _H , C _F , C _R arranged on different shafts as described above have the longitudinal axes of the transmission as shown in FIG. They are arranged so as to be located on the same plane (on the same plane in the vertical direction in FIG. 1) that is perpendicular to the direction (the horizontal direction in FIG. 1).

Incidentally, the output shaft S ₃ at the output side (the right end in the drawing) is connected to a differential device M of the vehicle and is configured to rotate the drive wheels (not shown) at a rotational speed which is the speed change in the transmission.

Therefore, the transmission for the industrial vehicle having the above configuration is
The clutch C _H of the high-speed switching is on the counter shaft S _2, respectively to the clutch C _F for advancing on the output shaft S _3, also clutch C _R for reverse travel on the second counter shaft S ₂ 'disposed Further, since the clutches C _H , C _F , C _R are arranged so as to be located on the same plane perpendicular to the longitudinal direction of the transmission, the length of the transmission in the longitudinal direction of the transmission can be reduced. It can be configured as short as possible. As a result, even a transmission having two forward gears and two reverse gears can have the same length as a conventional transmission having one forward gear and one reverse gear.

By the way, the clutches C _H , C of the transmission having the above-mentioned structure
_F and C _R operate as follows via the hydraulic circuit shown in FIG. 5 under the control of the control device.

That is, the clutch C _H for high-speed switching has the solenoid valve 1 of the hydraulic circuit shown in FIG. 5 when the lever 1A for high-low speed switching in FIG. 6 is in the “D” (automatic shift state) position.
ON / OFF of the clutch for forward and reverse
C _F and C _R are each configured to be operated by the operation of the manual switching valve 2. The solenoid valve 1 and the manual switching valve 2 are connected to a hydraulic pressure generating pump P as shown in the hydraulic circuit of FIG.

That is, the hydraulic pressure generation pump P (see FIG. 1 and FIG. 2) attached to the torque converter T is connected via the pipe L ₁ and the pipe L ₂ branched from the pipe L ₁ and the throttle valve 3. It is connected to a manual switching valve 2, and this switching valve 2 is operated from the hydraulic pressure generating pump P by operating the lever 2A for selecting three positions, and any one of the forward and reverse clutches C _F , C _R described above is selected. The crab is configured so that pressure oil can be selectively supplied.

Further, as shown in FIG. 5, the conduit L ₂ is branched at the base end side thereof and is connected to the solenoid valve 1 via the conduit L ₃ equipped with the throttle valve 4. This solenoid valve 1 is electrically connected to the control device 10 when the lever 1A for switching between high speed and low speed shown in FIG. It is configured to open and close under the control of the control to supply / disconnect pressure oil to the above-mentioned high speed switching clutch C _H.

Further, as shown in FIG. 5, the tip end side of the pipeline L ₁ has a pressure regulating valve 5 for maintaining a constant pressure on the downstream side.
Connected to the above-mentioned torque converter T via A, 5B,
After that, it is connected to return to the reservoir tank 8 through the oil cooler 6 and the filter 7.

The pipe line L ₁ from the hydraulic pressure generation pump P is branched by the pipe line L ₄ on the front side of the branched portion with the pipe line L _2, and the pipe line L ₄ is connected to the reservoir tank via the pressure regulating valve 9. It is connected back to 8 and is configured to maintain a constant pressure throughout this hydraulic circuit.

Further, in the case of the transmission according to the present embodiment, the clutches C _H , C _F , C _{R are} arranged in order to reduce the shock generated during the gear shifting.
The accumulators A are arranged in parallel with each other.

Thus, in the present transmission configured as described above, when the high / low speed switching lever 1A (see FIG. 6) is in the "D" position, the operator's forward / backward switching lever is changed during traveling. By the operation and the control of the control device, the gear shift operation is performed as described below, and the engine brake is activated or released. That is, while the engine is operating, the operator follows the operation pattern shown in FIG.
(See Fig. 6), for example, when operating forward,
The spool of the switching valve 2 in FIG. 5 is moved to the right side in FIG. 5, and the pressure oil from the hydraulic pressure generation pump P is transferred to the pipeline L ₁ ,
It is supplied to the forward clutch C _F via L ₂ , the throttle valve 3, and the switching valve 2, and the gear G ₈ is fixed (connected) to the output shaft S ₃ in FIG. Therefore, from the input shaft S ₁ and the counter shaft S ₂ which are constantly rotating in a state where the engine is operating, the output shaft S ₃ is rotated via the gear G ₈ and the gear G ₅ meshing with the gear G _8. It is transmitted and can travel forward. At this time, the control device 10 detects how much the throttle of the accelerator is opened and the rotational speed N ₃ of the output shaft S ₃ side at that time, and determines that it is within the traveling condition at the low speed stage. fast a case, the clutch C _H of the high-speed switching to OFF is run in a state of low speed stage, and if it is determined to be within the driving conditions of the high-speed stage, and the oN clutch C _H of the high-speed switching Run in steps. Therefore, in the traveling state in the low speed stage, the rotation from the input shaft S ₁ to the counter shaft S ₂ is transmitted through the freewheel F, and in the traveling state in the high speed stage, the input shaft S ₁ to the counter shaft S ₂ The rotation is transmitted to the high speed switching clutch C _H.

Then, in the traveling state at the low speed stage, when engine braking such as downhill is necessary, the control device 10 detects and judges the situation as described later, and when engine braking is necessary. The high speed switching clutch C _H is turned on, the counter shaft S ₂ and the input shaft S ₁ are connected via the clutch C _H , and the axle side, that is, the output shaft S ₃ side is connected to the engine output shaft S _{3. e}
Connect to and make the engine brake available.

The series of operating conditions in the forward running also occurs during the backward running, and therefore, the engine braking can be similarly obtained even in the running state at the low speed stage of the backward running. still,
When the lever 1A for switching between the high speed and the low speed in FIG. 6 is positioned at "1", traveling at low speed is performed, and when it is positioned at "2", traveling at high speed is performed.

The operation statuses of the clutches C _H , C _F , C _R and the freewheel _F at each speed stage from the first forward speed to the second reverse speed of the present transmission are summarized in FIG. In FIG. 4, the mark “◯” indicates the operating state and the mark “no” indicates the non-operating state.

By the way, the above-described control device 10 has the high / low speed switching lever 1A.
Is located at the position of "D", it can be controlled so as to apply the engine brake as follows when traveling in the forward or reverse low speed stage. That is, during low-speed running from t _-1 to t _{0 in} FIG. 8 (when the high-speed switching clutch C _H is OFF), for example, a downhill road is entered and the accelerator throttle (not shown) becomes idle. and the (first reference t ₀ point of Figure 8) detecting a relative rotational speed N _G4 rotational speed N ₂ and the gear G ₄ of the counter shaft S _2, this value is equal, i.e., from the traveling wheel side these values become equal rotational speed N ₂ of the counter shaft S ₂ by the inertia force is reduced the rotational speed N _G4 elevated gear G ₄ (see t ₁ point Figure 8)
And turning on the solenoid valve 1 of the hydraulic circuit shown in FIG.
After FF operation (modulation operation), pressure oil is gradually supplied to the clutch C _H for high speed switching (see the pressure diagram of clutch C _H in FIG. 8). Then, by comparing the rotational speed N _e of the output shaft S _e of the input shaft S ₁ of the rotational speed N ₁ and the engine, equal this value, i.e., the input shaft S ₁ by the inertia force from the traveling wheel (axle) side and the rotational speed N _e of the output shaft S _e of the rotational speed N ₁ increases the engine is equal to these values decreased (see t ₂ points Figure 8), the solenoid of the hydraulic circuit shown in FIG. 5 Valve 1
Is always turned on (fully open) to change the clutch C _H for high-speed switching.
Control is performed so that pressure oil having a predetermined pressure (a pressure value sufficient to operate the clutch C _H ) is supplied to the. In result, the low-speed drive position, when required engine braking, via the clutch C _H of the high-speed switching, the output shaft side of the axle side and the engine is connected, it is possible to smoothly and effectively engine braking.

On the other hand, in the state, the accelerator throttle is turned ON (see t ₅ points Figure 8), the control unit 10 detects the change, the output shaft of the rotational speed N ₁ and the engine input shaft S ₁ S compares the rotational speed N _e of _e side, this value is equal, i.e. the rotational speed N ₁ of the speed N _e is increased input shaft S ₁ of the output shaft S _e side of the engine by the throttle operation is lowered these values are equal (see t ₆ points Figure 8), the solenoid valve 1 of the hydraulic circuit shown in FIG. 5 in the OFF (closed), to stop the pressure oil to the clutch C _H of the high-speed switching To control. As a result,
When the high speed switching clutch C _H is turned off, power is transmitted from the engine side to the axle side through the freewheel F, and the transmission is in a low speed running state (see point t _{7 in} FIG. 8). You will drive. In the above-mentioned series of control states, the horizontal axis represents time (elapsed time) and running condition, and the vertical axis represents throttle state (throttle ON-OFF) and respective rotation speeds N _e , N ₁ , N _G4, and N _2, the supply state of hydraulic oil to the clutch C _H of the high-speed switching, expressed taking respectively, it becomes as shown in Figure 8. The two-dot chain line in FIG. 8 shows the state of change in the number of revolutions thereafter when not controlled.

Further, the control unit 10 controls the throttle state of the accelerator and the rotational speed of the output shaft S ₃ or the counter shaft S ₂ at that time.
N _3, detects the N _2, when and opens a predetermined or higher acceleration throttle the rotational speed N _3, N ₂ is more than predetermined value, actuates the solenoid valve 1, the clutch C _H of the high-speed switching Turn on to automatically switch from the low-speed running state to the high-speed running state. This switching is performed by duty control as shown in each of FIG. 7 so that the switching can be performed smoothly. That is,
When a signal for turning on the clutch C _H for high speed switching is input (see FIG. 7 (a) t ₀ ), the control device 10 first supplies the hydraulic oil to the hydraulic circuit as shown in FIG. 7 (b). Yukiwataru (Figure 7 (b), (c) refer to t ₁₎ fully opening the solenoid valve 1 to the (duty ratio 100%), the return from the fully closed and Yukiwataru to being opened a little, the contact state of the clutch C _H From the time until it is completely connected (Fig. 7 (b), (c) t ₁ → t ₂
Refer to) Perform duty ratio control so that it is performed at a slow speed, then continue duty ratio control until clutch C _H is fully activated, and finally reach 100% duty ratio.
To

According to the speed change device of the present embodiment, in addition to the above-described action and effect peculiar to the present invention, a shift of two forward gears and two reverse gears capable of operating the engine brake can be obtained. Also, in the case of this transmission, the ON-OFF timing of the clutch C _H for high speed switching during engine brake operation is set as described above (as shown in FIG. 8), and it is turned on during engine brake operation.
-Since the so-called modulation operation is performed by OFF duty control, and the above duty control (see FIG. 7) is performed when the pressure oil is supplied to the clutch C _H for high-speed switching during normal gear shifting operation. In addition to the arrangement of the actuators, there is almost no impact due to these gear shifting operations.

Further, as another embodiment, instead of the embodiment shown in FIG. 1, a high speed switching clutch C _H may be arranged on the input shaft S ₁ as shown in FIG. It is possible to obtain the same operational effect as.

Further, in the embodiment shown in FIGS. 1 and 2, even if the free wheel is arranged on the input shaft side, the same effect as that of the above embodiment can be obtained. For example, in the transmission of the embodiment shown in FIG. 1, even if the freewheel is arranged on the input shaft side as shown in FIG. 9, the same effect as that shown in FIG. 1 can be obtained. be able to.

Further, although the embodiments shown in FIGS. 1 and 2 are described by taking the type in which the transmission is equipped with a torque converter as an example, a pure mechanical type is used instead of the torque converter. Even if the clutch C ₀ is provided and controlled by the control device at the time of gear shifting, as in the above embodiment, one freewheel F and three clutches C _H , C _F , C _R
It is possible to obtain an automatic transmission that is capable of performing two forward gear shifts and two reverse gear shifts and that can obtain engine braking even when traveling at a low gear. For example, instead of the transmission of FIG.
It can be configured as shown in the figure.

According to the present invention, as described above, in the automatic transmission device of the torque converter type or the pure mechanical type having the two forward gears and the two reverse gears, four clutches are required.
With one clutch C _H , C _F , C _R and one freewheel F, it is possible to shift forward 2 speeds and reverse 2 speeds, and at the same low speed and high speed as the conventional transmission equipped with the above 4 clutches. It is possible to obtain engine braking during traveling, and as a major feature, it can be reduced to the same size as a conventional transmission having one forward gear and one reverse gear.

(Advantages of the Invention) The transmission for an industrial vehicle according to the present invention is configured as described above and produces the action.
An industrial vehicle equipped with a transmission of two gears can be equipped with a transmission of two forward gears and two reverse gears composed of three clutches and one free wheel without changing the size of the vehicle body.

For this reason, it is possible to provide an industrial vehicle having one forward and one reverse and two forward and two reverse without changing the design of the vehicle body itself, and it is possible to improve productivity by using common parts. It is possible for the user to make a selection according to his / her working mode.
As a result, one clutch can be reduced compared to the conventional one shown in FIG.
It is possible to inexpensively supply an industrial vehicle equipped with a transmission of multiple gears.

Further, since the length of the transmission in the longitudinal direction of the shaft is short, it is possible to mount the transmission having two forward gears and two reverse gears even in a small industrial vehicle used in a narrow passage or the like. The improvement of workability can be expected for a user having an industrial vehicle used in.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing the construction of a torque converter type two-stage forward transmission and two reverse type automatic transmission according to the present invention, and FIG. 2 is a torque converter type two-stage forward transmission showing another embodiment according to the present invention. FIG. 3 is a skeleton diagram showing the configuration of a reverse two-stage automatic transmission, and FIG. 3 is a skeleton diagram showing the configuration of a pure mechanical two-stage forward two-stage automatic transmission according to another embodiment of the present invention. FIG. 4 is a table showing the operating state of each clutch and the freewheel when forming each shift stage of two forward gears and two reverse gears, and FIG. 5 is for operating each clutch of the transmission shown in FIG. 6 is a circuit diagram showing the configuration of the hydraulic circuit of FIG. 6, FIG. 6 is a diagram showing a shift pattern of the transmission shown in FIG. 1, and FIGS. 7 (a), (b), and (c) are duty control states. Fig. 7 (a) is a diagram for
Is a diagram in which the abscissa represents time and the ordinate represents a shift signal. FIG. 7 (b) represents a diagram in which the abscissa represents time and the ordinate represents a control signal, and FIG. 7 (c). Is a diagram in which the horizontal axis represents time, and the vertical axis represents hydraulic pressure generated in the high speed switching clutch. FIG. 8 is a control before and after the engine brake is operated during low speed running of the transmission shown in FIG. The horizontal axis represents time (elapsed time) and running condition, and the vertical axis represents the rotation speed N _e , N ₁ ,
And N _2, N _G4, the accelerator throttle state (the throttle
ON-OFF) and the operating state represented by the supply of pressure oil to the high speed switching clutch C _H. Fig. 9 shows the present invention when the freewheel is arranged on the input shaft side. Fig. 10, Fig. 10, Fig. 10 showing the configuration of a torque converter type two-speed forward and two-speed reverse transmission showing another embodiment according to the present invention.
FIG. 11 is a skeleton diagram showing a configuration of a transmission according to a conventional example of an automatic transmission having two forward gears and two reverse gears. S _e …… Engine output shaft side, S ₁ …… Input shaft, S ₂ …… Counter shaft, S ₂ ′ …… Second counter shaft, S ₃ …… Output shaft,
G ₂ , G ₄ …… High-speed gear train, G ₁ , G ₃ …… Low-speed gear train,
C _H …… High speed switching clutch, C _F …… Forward clutch, C _R …… Reverse clutch, F …… Freewheel.

Claims (1)

[Scope of utility model registration request] 1. A high-speed gear train is provided between a high-speed gear train and a counter shaft via a high-speed switching clutch C _{H so as} to selectively transmit power at a high-speed stage or a low-speed stage. The gear train for low speed is arranged between the input shaft of the transmission and the counter shaft via a freewheel F that transmits rotation only from the input shaft to the counter shaft side,
At least two gear trains for transmitting the rotational force from the counter shaft to the output shaft through the forward clutch C _F and the reverse clutch C _R are separately provided between the counter shaft and the output shaft. A transmission device for an industrial vehicle, which is configured to be capable of two forward gear shifts and two reverse gear shifts with the above three clutches and one free wheel, and is provided downstream of a counter shaft in a rotational force transmission path from the input shaft. , A second counter shaft and an output shaft are arranged in parallel to the input shaft and the counter shaft, and a forward gear train is provided between the counter shaft and the output shaft via a forward clutch C _F. And a reverse clutch C _R between the counter shaft and the second counter shaft.
And a gear train for meshing with each other for transmitting the rotational force for the reverse travel is fixedly provided on each of the second counter shaft and the output shaft. , A clutch C _H for high speed switching arranged on either the input shaft or the counter shaft, and a forward clutch C _F arranged on either the counter shaft or the output shaft and a counter shaft or a second counter shaft And the reverse clutch C _R disposed in any one of the above-mentioned positions are separately disposed on any one of the shafts and located in the same plane orthogonal to the longitudinal direction of the shaft of the transmission. Transmission for industrial vehicles.