JPH0756325B2 - Transmission for industrial vehicles - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for industrial vehicles such as forklifts, and more particularly to a transmission with two forward gears and two reverse gears for automatic transmission.

(Prior Art) In recent years, similar to passenger cars, industrial vehicles such as forklifts are beginning to be equipped with automatic transmissions due to their ease of operation.

For example, there is an automatic transmission for an industrial vehicle having two forward gears and two reverse gears as shown in FIG. 5 (actual Kaihei 1-78754).
issue).

That is, in this transmission, the input side (pump) of the torque converter T is connected to the output shaft S _{e of the} engine (not shown),
The output side (turbine side) shaft S _{T of} this torque converter _T
In addition to disposing the gear G ₁ on the input shaft S ₁ integrated with
Further, a first counter shaft S ₂ ′, a second counter shaft S ₂ ″ and an output shaft S ₃ are arranged in parallel with the input shaft S ₁ , and the gear G ₁ is connected to the first counter shaft S ₂ ′. The meshing gear G ₂ is fixed, and the first counter shaft S ₂ ′ has a gear on the output side that can be intermittently connected.
Forward and reverse low speed clutch equipped with G ₃ and G ₄
C _FL and C _RL are respectively arranged, and gears G ₆ and G ₇ meshing with the gears G ₃ and G ₄ are provided on the output side, which can be intermittently connected, for high speed forward and reverse clutches C _FH and C _RH . The second counter shaft S ₂ ″
And a gear G ₅ meshing with the gear G ₁ is fixed to the second counter shaft S ₂ ″, and the gear of the first counter shaft S ₂ ′ is provided on the output shaft S _3. Gears G ₈ and gears that mesh with G ₃ , G ₄ and the gear G ₆ of the second counter shaft S ₂ ″, respectively.
G ₉ is fixed, and the four clutches C _FL , C _RL , C are controlled by a control device (not shown) according to the selected position of the shift lever.
One or two of _FH and _CRH are selectively turned ON as appropriate to perform automatic shifting of two forward gears and two reverse gears.

(Problems to be solved by the invention) However, disposing the four clutches in the transmission as described above increases the number of clutches, which are relatively expensive parts, and the clutches to be controlled during shifting. , The control relationship becomes complicated, etc.
This increases the cost of the transmission.

The present invention has been made in view of the above-mentioned current situation, and
An object of the present invention is to provide a transmission having the same function as above by disposing three clutches and one free wheel instead of one clutch.

(Means for Solving the Problem) In the industrial vehicle transmission according to the invention of claim 1, the low speed gear G ₁ is fixed on the input shaft to which the rotation from the output shaft side of the engine is transmitted. High speed switching clutch G _H equipped with a high speed gear G ₂ on the output side
And a free wheel F for transmitting rotation from the input shaft side to the counter shaft side is provided on the counter shaft parallel to the input shaft, the gear G ₃ meshing with the gear G ₁ is provided on the input side. as well as set and fixed gears G _4, which meshes with the gear G _2, the clutch C _F for forward having a gear G ₅ in and intermittently closable output side, the gear G ₆ intermittent freely output side A reverse clutch C _R is provided, and on the output shaft parallel to the input shaft and the counter shaft, a mesh G ₇ meshing with the gear G ₅ , and
A industrial vehicle transmission device two-forward reverse two-stage fixedly provided respectively gear G ₈ which meshes through a gear G ₉ in the meshing G _6, the high-speed switching by ON or OFF control operation of the solenoid valve 1 When the control device that controls the solenoid valve 1 detects that the accelerator is in the idle state when the hydraulic oil is supplied or stopped to the clutch C _H for the vehicle, the input is input. Rotational speed of the shaft N ₁ and rotational speed of the gear G ₂ of the clutch for high speed switching above
Comparing G _G2, these values are equal, and modulation operating the solenoid valve 1 is supplied gradually pressurized oil to the clutch C _H, the clutch C _H of the high-speed switching than the rotational speed N ₁ of the input shaft When the number of rotations N _G2 of the gear G ₂ is increased, the solenoid valve 1 is turned on and the clutch C _H is turned on.

(Operation) Therefore, the industrial vehicle transmission according to claim 1 configured as described above operates the clutches C _H , C _F , and C _R at the time of gear shifting to thereby set the forward two-stage gear as follows. It is possible to obtain two reverse shifts and to obtain engine braking when required during low speed traveling.

That is, the forward first speed in the case of obtaining a (low speed stage) is fast switching OFF the clutch C _H of changeover, ON clutch C _F for forward, if the OFF clutch G _R for reverse, engine output Rotation from the shaft side is caused by gear G ₁ and gear G ₃ meshing with it from the input shaft.
Is transmitted to the counter shaft through a free wheel F equipped with a gear, and the output from the counter shaft is output via a forward clutch C _F equipped with a gear G ₅ on the output side and a gear G ₇ meshing with the gear G _5. Can be transmitted to the shaft.

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. The rotation from the side is the clutch C _H equipped with a gear G ₂ from the input shaft and the gear
Is transmitted to the counter shaft through the gear G ₄ which meshes with G _2, from the counter shaft via the gear G ₇ which meshes with the clutch C ₇ and the gear G ₅ for forward having a gear C ₅ on the output side , Can be transmitted to the output shaft. 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, the forward drive clutch C _F is turned off, and the reverse drive clutch C _R is turned on. The rotation from the side is transmitted to the counter shaft from the input shaft through the freewheel F having the gear G ₁ and the gear G ₃ meshing with the gear G _1, and from this counter shaft, the reverse drive having the gear G ₆ on the output side is performed. It is possible to transmit to the output shaft via the clutch C _R for gears and the gears G ₉ and G ₈ meshing with the gear G ₆ .

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 G _R ON to output the engine. rotation from the shaft side is transmitted via the gear G ₄ which meshes from the input shaft to the clutch C _H and a gear G ₂ provided with the gear G ₂ to the counter shaft,
From this counter shaft, a reverse clutch C _R equipped with a gear G ₆ on the output side, and a gear G ₉ and a gear G ₈ meshing with this gear G _6.
Can be transmitted to the output shaft. In this case, the freewheel F spins idle (is rotatable) because it can be rotated faster through the high speed switching clutch C _H.

As described above, the conventional four gear clutches are used to obtain the two forward and two reverse gears, but only three clutches and one freewheel are used, and only three clutches are controlled (operated). , Can perform the same function.

Further, in the transmission having the above configuration of the present invention, in the initial stage of the desired state of engine braking during low speed traveling,
Since the high speed switching clutch is gradually turned on and thereafter the high speed switching clutch is turned on, it is possible to obtain effective engine braking without shock in the initial state.

Of course, it is natural that the engine brake can be obtained during high-speed traveling in which rotation is transmitted via a clutch capable of transmitting rotation to both.

Further, according to the industrial vehicle transmission of claim 2, when the engine brake is operating during low speed traveling and the engine brake becomes unnecessary, the high speed switching clutch is turned off. The engine brake can be released automatically.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a skeleton diagram showing a configuration of a torque converter type two-stage forward and two-way reverse automatic transmission according to the present invention, and FIG. 2 is a hydraulic circuit for operating a clutch of the transmission shown in FIG. It is a figure.

In FIG. 1, S ₁ is an input shaft, S ₂ is a counter shaft, S ₃ is an output shaft of a transmission, and these shafts S ₁ , S ₂ , S ₃ are arranged in parallel to 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).

On the input shaft S ₁ , a gear G ₁ is fixedly installed, and a clutch C _H for high speed switching, which is provided with a gear G ₂ on the output side which can be intermittently connected, is arranged. Therefore, when the clutch C _H for high speed switching is ON, the gear G ₂ is fixed to the input shaft S ₁ , and when the clutch C _H is OFF, the gear G ₂ is relative to the input shaft S ₁ . It becomes rotatable.

The aforementioned counter shaft S _2, freewheeling F input shaft S ₁ provided with the gear G ₃ to the gear G ₁ and meshed with the input shaft
From the counter shaft S ₂ side so that it can be driven,
Forward clutch with gear G ₅ on the output side that can be intermittently connected
C _F and a reverse clutch C _R equipped with a gear G ₆ on the output side which can be intermittently connected are arranged, and a gear G ₄ meshed with a gear G ₂ on the input shaft S ₁ is fixed. There is. Therefore, in the free wheel F, between the input shaft S ₁ and the counter shaft S ₂ , the rotation speed due to the meshing path of the gear G ₁ and the gear G ₃ is the clutch.
It functions to transmit the rotation from the input shaft S ₁ to the counter shaft S ₂ only when the rotation speed is faster (greater) than that of the meshing path of the gear G ₂ and the gear G ₄ of C _H. Also, the forward clutch C _F
Clutch for reverse and C _R is the gear G _5, G ₆ each clutch is provided therein when the ON is fixed to the counter shaft S ₂ respectively, whereas the gear G ₅ is provided therein when the OFF, G ₆
Becomes rotatable with respect to the counter shaft S ₂ .

The aforementioned output shaft S _3, a gear G ₇ which meshes with the gear G ₅ of the counter shaft S _2, the gear G ₈ which meshes are fixed similarly to the gear G ₆ through the gear G _9.

Then, the output shaft S ₃ is connected to a differential device D of the vehicle on the output side (the right end in the drawing).

The high speed switching clutch C _H is operated by turning on and off the solenoid valve 1 in the hydraulic circuit shown in FIG. 2, and the forward and reverse clutches C _F and C _R are operated.
Is configured to be operated by the operation of the manual switching valve 2.

The hydraulic circuit that operates each clutch will be described with reference to FIG. 2. The hydraulic pressure generation pump P attached to the above-mentioned torque converter T (see FIGS. 1 and 2).
Is connected via a line L ₂ provided with the by throttle valve 3 branching from line L ₁ and the line L ₁ to the switching valve 2 of manual, the switching valve 2, 3 position lever for selection By operating 2A, pressure oil can be selectively supplied from the hydraulic pressure generation pump P to the forward and reverse clutches C _F and C _R.

As shown in FIG. 2, the conduit L ₁ is further branched at the tip end side thereof, and is connected to the solenoid valve 1 via the conduit L ₃ equipped with the throttle valve 4. The solenoid valve 1 is electrically connected to the control device 10 and is opened and closed under the control of the control device 10 which will be described later to supply pressure oil to the above-described high speed switching clutch C _H.

Further, as shown in FIG. 2, the tip end side of the pipe line L ₁ is a pressure regulating valve 5 for maintaining a constant pressure on the downstream side.
Is connected to the above-described torque converter T via the oil cooler 6 and then to the reservoir tank 8 via the oil cooler 6 and the filter 7.

Then, the line L ₁ from the hydraulic pressure generation pump P is
This line is branched off by the line L ₄ on the front side of the line L _2.
L ₄ is connected to the reservoir tank 8 via a pressure regulating valve 9 so as to maintain a constant pressure in the entire hydraulic circuit. In FIG. 2, reference numeral 15 is an operation valve for manual inching used when the fork is lifted by a forklift.

By the way, the above-described control device 10 controls to apply the engine brake in the following manner when traveling in the forward or reverse low speed stage. That is, at low speed running from t _-1 to t _{0 in} FIG. 3 (when the high speed switching clutch C _H is OFF),
For example descending enters the slope of the accelerator throttle (not shown) is idle when (the reference three views of t ₀ point) detecting a input shaft S ₁ rpm N ₁ and the high-speed switching compares the rotational speed N _G2 of the gear G ₂ of the clutch C _H, the rotational speed N ₁ this value is equal, i.e. the rotational speed N _G2 gear G ₂ is increased by the inertia force from the traveling wheel side input shaft S ₁ Is decreased and these values become equal. And (a 3 t reference _point of view), the hydraulic circuit solenoid valve 1 the ON-OFF shown in FIG. 2 (open) operation with (modulation), the clutch C _H of the high-speed switching
Begin to gradually supply pressure oil to the clutch (see the pressure diagram of clutch C _H in Fig. 3). And the gear of clutch C _H for high speed switching
Compares the rotational speed N _e of the output shaft S _e of the rotational speed N _G2 and an engine of G _2, equal this value, i.e., the running wheels (wheel) rotational speed of the gear G ₂ by the inertia force from the side N _G2 always oN but elevated and these values become equal speed N _e of the output shaft S _e of the engine is reduced (see FIG. 3 of t ₂ points), the solenoid valve 1 of the hydraulic circuit shown in FIG. 2 The valve is operated (fully open) to control the high speed switching clutch C _H so as to supply pressure oil of a predetermined pressure (a pressure value sufficient to operate the clutch C _H ). As a result, in the low-speed traveling position, when the engine brake is required, via the high-speed switching clutch C _H ,
The axle side and the output shaft side of the engine are connected.

On the other hand, in the state, the accelerator throttle is turned ON (see t ₅ points of FIG. 3), the control unit 10 detects the change, the solenoid valve 1 of the hydraulic circuit shown in FIG. 2
In the OFF (closed), control to stop the pressure oil to the clutch C _H of the high-speed switching. As a result, the clutch C _H for high-speed switching is turned off, the operation of the transmission is transmitted from the engine side to the axle side via the freewheel F, and the vehicle is running at a low speed (see point t _{7 in} FIG. 3). ) Will be driven by. 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), each rotation speed N _e , N ₁ , and high speed. The supply state of the pressure oil to the switching clutch C _H is shown in FIG. 3 respectively. The alternate long and two short dashes line in FIG. 3 shows the state of change in the number of revolutions thereafter when not controlled.

Further, the control device 10 controls the throttle state of the accelerator and the rotational speeds N ₃ and N of the output shaft S ₃ or the counter shaft S ₂ at that time.
_{When 2} is detected, the throttle of the accelerator is opened more than a predetermined value and the number of rotations N ₃ , N ₂ is a value more than a predetermined value, the solenoid valve 1 is operated and the high speed switching clutch is operated.
It is configured to turn on C _H and automatically control to switch from a low-speed running state to a high-speed running state.

Therefore, the present transmission configured as described above performs the following speed change operation during traveling, and also operates so that the engine brake is operated or released. That is, when the operator operates the forward / reverse switching lever 2A (see FIG. 2) while the engine is operating, for example, to the forward side, the spool of the switching valve 2 in FIG. Moving to the left side in FIG. 2, the pressure oil from the hydraulic pressure generation pump P is supplied to the forward clutch C _F via the pipe lines L ₁ and L ₂ , the throttle valve 3 and the switching valve 2, and in FIG. The gear G ₅ is fixed (coupled) to the counter shaft S ₂ . Therefore, the input shaft that is constantly rotating while the engine is operating
From S ₁ and the counter shaft S _2, via a gear G ₇ which meshes with this and the gear G _5, is rotated transmitted to the output shaft S _3, it is possible to forward running, this time, the control device 10, If it is determined that the accelerator throttle is open and the rotation speed N ₃ of the output shaft S _{3 at} that time, etc. Clutch C _H
Is run in a state of low speed stage to OFF, If it is determined to be within the driving conditions of the high-speed stage, the clutch C _H of the high-speed switching
Turn on to drive in the high speed stage. 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 free wheel 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 the engine braking such as downhill is necessary, the control device 10 detects and judges as described above, and when the engine braking is necessary, the high speed driving is performed. The clutch C _H for switching 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 output shaft S _e of the engine. Then
Put in a state where the engine brake is obtained.

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.

According to the speed change device of the present embodiment, as described above, it is possible to obtain a speed change of two forward speeds and two reverse speeds at which engine braking can be performed. In the case of the transmission apparatus, is set to the timing of the ON-OFF of the clutch C _H of the high-speed switching as described above, also, the pressure oil supply to the clutch C _H of the high-speed switching In this case, since the ON-OFF operation is repeated while being so-called modulation, there is a feature that almost no impact due to these operations occurs.

By the way, in the above-mentioned embodiment, the transmission is equipped with the torque converter as an example for explanation. However, instead of the torque converter, the control device is operated as shown in FIG. Even if the mechanical clutch C ₀ is provided, one forward wheel F and three clutches C _H , C _F and C _R can be used to shift gears in two forward gears and two reverse gears as in the above embodiment. It is possible to obtain an automatic transmission that can obtain engine braking even when traveling at a low speed.

As described above, the present invention requires four clutches in the automatic transmission device of the torque converter type or the pure mechanical type, which has two forward and two reverse gear shifts.
With two clutches C _H , C _F , C _R and one freewheel F, it is possible to shift gears in two forward gears and two reverse gears, and in the same low speed and high gear as the conventional transmission equipped with the above four clutches. It is possible to obtain engine braking during traveling.

(Advantages of the Invention) Since the industrial vehicle transmission according to the present invention is configured and operates as described above, it is possible to reduce the number of clutches, which are expensive parts in the transmission, and Since the number of clutches to be controlled in the automatic transmission can be reduced, the automatic transmission can be provided at a considerably lower cost than conventional ones.

Moreover, in terms of functionality, it is no different from conventional automatic transmissions, and engine braking can be obtained even when traveling at low speeds.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a configuration of a torque converter type two-stage forward and two-way reverse automatic transmission according to the present invention, and FIG. 2 is a hydraulic circuit for operating a clutch of the transmission shown in FIG. FIGS. 3A and 3B show the control states before and after the engine braking of the transmission shown in FIGS. 1 and 2, in which the horizontal axis represents time (elapsed time) and the running state, and the vertical axis represents each of the above rotations. Fig. 4 is a pressure diagram showing the number N _e , N ₁ , the accelerator throttle state (throttle ON-OFF), and the pressure oil supply state to the clutch C _H for high-speed switching. FIG. 5 is a skeleton diagram showing the structure of an automatic transmission device according to another embodiment of the invention, and FIG. 5 is a skeleton diagram showing the structure of a conventional two-stage forward two-stage reverse gear automatic transmission. S _e …… Engine output shaft side, S ₁ …… Input shaft, S ₂ …… Counter shaft, S ₃ …… Output shaft, G ₁ , G ₂ , G ₃ , G ₄ , G ₅ , G ₆ , G ₇ , G ₈ , G ₉ …
… Gears, C _H …… High speed switching clutch, C _F …… Forward travel clutch, C _R …… Reverse travel clutch, F …… Free wheel.

Claims (2)

[Claims] 1. A high speed switching device comprising a low speed gear G ₁ fixedly mounted on an input shaft to which rotation is transmitted from an output shaft side of an engine and a high speed gear G ₂ provided on an intermittent output side. A clutch C _H is provided, and a gear G ₃ that meshes with the gear G ₁ is provided on the input side on a counter shaft parallel to the input shaft, and the rotation is transmitted from the input shaft side to the counter shaft side. A gear provided with a wheel F and meshing with the gear G ₂
A forward clutch C _F having G ₄ fixedly installed and a gear G ₅ provided on the output side which can be intermittently connected, and a reverse clutch C _R having a gear G ₆ provided on the output side which can be intermittently connected are provided. A forward gear 2 in which a gear G ₇ meshing with the gear G ₅ and a gear G ₈ meshing with the gear G ₆ via a gear G ₉ are fixed on the output shaft parallel to the input shaft and the counter shaft 2 A two-stage reverse gear transmission for an industrial vehicle, which is configured to supply or stop pressure oil to the high speed switching clutch C _H by ON or OFF control operation of a solenoid valve 1, and to drive at a low speed. sometimes, the control device for controlling the solenoid valve 1 detects that the accelerator is idle, the rotational speed N _G2 of the gear G ₂ of the clutch rotational speed N ₁ and the high-speed switching of the input shaft Compare and if these values are equal, the solenoid bar The Bed 1 and modulation operations to supply gradually pressurized oil to the clutch C _H, the rotational speed of the gear G ₂ of the clutch C _H of the high-speed switching than the rotational speed N ₁ of the input shaft
A transmission for industrial vehicles having two forward gears and two reverse gears, which is configured to turn on the solenoid valve 1 and turn on the clutch C _H when N _G2 becomes high. 2. When the throttle of the accelerator is turned on, the solenoid valve 1 is turned off to stop the supply of the pressure oil to the high speed switching clutch C _H. The transmission for industrial vehicles according to 1.