JPH03172625A - Power take-off operation mechanism for specially equipped vehicle - Google Patents

Abstract

PURPOSE:To make the beginning of engagement smooth and quick by transmitting a pull-directional operation force of an electric motor via a force accumulation means of a variable length damping type to a shifter of a power take-off, and making a ring gear engage with a power transmission gear. CONSTITUTION:Power from an engine 3 is transmitted via a transmission 4 to a power take-off gear secured to an input shaft 2 of the power take-off 1. When an electric motor 9 is driven, its operation force in the pulling direction causes, via an operation rod 7 and a force accumulation means 10 of a variable length damping type, a shifter in engagement with only the power take-off gear to shift. When the shifter begins to engage with a ring gear, the force accumulation means 10 accumulates force while absorbing its deformation by the reactional force of the ring gear. When the accumulated force reaches its limit, the shifter engages with the ring gear, the power transmission gear begins to corotate, the accumulated force is released, and the shifter is made to engage with the power transmission gear. Thus noise is prevented from being produced and gear teeth surfaces are prevented from being damaged.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an operating mechanism for a power take-off device in a special purpose vehicle, and more specifically, what is the power transmitted from the engine output to the rear wheels from the transmission via the propeller shaft? Separately, when extracting the power for the hydraulic actuator that enables various operations on special vehicles from the transmission, it is possible to engage and disengage the rotating gear and the gear that meshes with it to transmit power, and supplies it to the hydraulic pump for the hydraulic actuator. This invention relates to an operating mechanism in a power extraction device that can connect and disconnect power.

[Conventional technology]

Specially equipped vehicles include dump trucks and the like that have a tilting loading platform at the rear of the vehicle body, and are equipped with a hydraulic actuator to tilt the loading platform. The engine power that is being driven while the vehicle is stopped is used to drive the hydraulic pump that supplies hydraulic oil to the actuator. In that case, the power extracted from the transmission passes through several gears and changes the meshing state of the gears.
The power can be transmitted to or cut off from the extraction shaft, and the hydraulic pump is driven by the rotation of the extraction shaft. For example, JP-A-57-58513 and JP-A-51-1
Japanese Patent No. 26628 and the like describe a power extraction device that is capable of extracting power for various works in addition to the power transmitted from the transmission to the rear wheels.

By the way, it has been easy to separately extract the above-mentioned power from the transmission, but
When a specially equipped vehicle is equipped with a transmission equipped with an automatic shift function, the power extraction operation becomes complicated. To put it simply, the operating procedure is that when the vehicle is stopped, the range switching lever located in the D range is set to the P range, and when the engine power is supplied to the hydraulic pump, the range switching lever is moved to the D range once. Then, while continuing to press the brake pedal, move the shifter that allows the gears that transmit power to interlock. Then, while removing the brake pedal, the range switching lever is switched from D range to N or P range.

On the other hand, when stopping the extraction of power, while depressing the brake pedal, switch the range selector lever from N or P range to D range, disengage the shifter and each gear, and while loosening the brake pedal, switch the range selector lever from N or P range to D range. Move the switching lever to N or P range again.

In this way, when extracting power for various tasks from an engine equipped with an automatic transmission, or when stopping the extraction,
It is necessary to operate the brake pedal and the range switching lever frequently, and there is a problem that the procedure becomes extremely complicated and troublesome. At that time, there is a risk of trouble if the brake pedal is pressed incorrectly, so caution is required when operating the brake pedal.

In addition, during the operation to extract power, there is a connection between a rotating gear and a stationary gear, and the connection is released, which can cause gear noise and damage to the tooth surface.
Improvement is strongly desired.

[Problem to be solved by the invention]

Therefore, in order to solve the above-mentioned drawbacks, the present applicant proposed in Japanese Patent Application No. 1-84334 a power take-off device that does not require complicated switching operations. This device is the fifth
As shown in Figure (C), a power transmission gear 15 is formed in order to transmit power from the power take-off gear 11, which transmits engine power and constantly rotates, to the power transmission gear 15 that drives the hydraulic pump. The synchronizer mechanism includes a ring gear 14 having a fitted conical surface 14b on the inner surface that can be fitted to and removed from the output conical surface 15b, and a shifter 16 that is movable so as to be able to mesh with any of the gears at the same time. Therefore, even in the case of a vehicle equipped with an automatic transmission, power can be extracted with a simple operation. that time,
The meshing state of the shifter with each gear can be changed by remote manual operation from the driver's seat or the like.

That is, the shifter 16 is initially engaged only with the power take-off gear 11, and when the shifter 16 shown in FIG. , after the shift internal teeth 16a of the shifter 16 mesh with the transmission external teeth 14a of the annular gear 14, they also mesh with the input external teeth 15a of the power transmission gear 15, and the shifter 16 is connected to the power take-off gear 119 and the annular gear 1.
4. Power extraction is achieved in a state where all of the power transmission gears 15 are engaged [see FIG. 5(C)]. that time,
By the fitting operation of the fitting conical surface 14b of the annular gear 14 and the output conical surface 15b of the power transmission gear 15, synchronization of rotations of the power take-off gear 11, that is, the shifter 16, and the power transmission gear 15 can be obtained. ing.

By the way, when the operating rod for moving the shifter 16 is displaced by an electric motor without a self-displacement absorption function, the shifter 16 is moved at a constant speed as shown by line Q in FIG. 6(C). . Returning to the device shown in FIG. 5(C), the shifter 16 is always rotating because it is meshed with the power take-off gear 11, but since the annular gear 14 is in a state where it can freely rotate, the shifter 16 is rotated. It is easy to completely mesh with the gear 14 [see point S on the dashed-dotted line in FIG. 6(d)]. During this time, the operating force acting on the operating rod changes as shown by the two-dot chain line point S in FIG. 6(C). During the meshing between the shifter 16 and the circular gear 14, the shifter 16 slightly moves the circular gear 14 toward the power transmission gear 15, so that the fitted conical surface 14b of the circular gear 14 is connected to the power transmission gear 15. Although not completely attached to the output conical surface 15b. Therefore, the power transmission gear 15 starts to rotate together with the rotation of the ring gear 14 to a point S indicated by a chain double-dashed line in FIG. 6(d).

Even after this state, the operating rod is displaced at a constant speed, so the shifter 16 also moves further toward the power transmission gear 15. It takes time Tl (see FIGS. 6(C) and (d)) to start meshing with the power transmission gear 15, and by achieving complete meshing between the shifter 16 and the annular gear 14, the shifter The force of the ring gear 16 pressing the ring gear 14 in the direction of the power transmission gear 15 suddenly decreases, and the fitting conical surface 14b of the ring gear 14 and the power transmission gear 1
Since the adhesion force with the output conical surface 15b of 5 is weakened,
During this time, the rotation of the power transmission gear 15 that was being rotated together decreases significantly from point S to point U shown in FIG. 6(d). When the shifter 16 starts to mesh with the power transmission gear 15 and the mesh is complete, the power transmission gear 15
rotates at a speed RO that is in balance with the driving force of the shifter 16, that is, the power take-off gear 11, and the power drives a hydraulic pump and the like.

In such an operation, the rotational speed of the power transmission gear 15 that has started rotating significantly decreases from Ra to RL shown in FIG. 6(d) because the shifter 16 has completed meshing with the ring gear 14. This is because the above-mentioned time T1 from when the gear starts to mesh with the power transmission gear 15 is long. Therefore, in order to raise the rotational speed to a predetermined number from when the shifter 16 first engages with the power transmission gear 15, it is necessary to increase the speed by the amount of RC shown in FIG. 6(d). As a result, there is an excessive difference in the rotational speed between the shifter 16 and the power transmission gear 15,
The synchronization becomes severe, causing noise such as gear noise and switching noise between the shifter 16 and the power transmission gear 15, and in some cases, problems such as damage to the tooth surfaces remain. The higher the rotational speed of the shifter 16 to which power from the engine is transmitted, and the greater the load applied to the power transmission gear 15, the more this will occur.

When manually displacing the operating rod that moves the shifter 16, it is possible that the displacement of the operating rod may change as soon as the shifter 16 and the power transmission gear 15 become confused due to the increased meshing reaction force. It won't happen if you slow down and slow down. However, if an electric motor is used to displace the operating rond in order to eliminate the hassle of manual operation, the operating rond will be moved at a uniform speed [see line Q in Figure 6(C)]. Even if there is a large meshing reaction force when the shifter 16 meshes with the power transmission gear 15, it is not possible to perform a slow meshing operation to reduce the force, resulting in gear noise or the like.

The present invention was made in view of the above-mentioned problems, and its purpose is to provide an extremely simple range switching operation when extracting power for performing various tasks in a specially equipped vehicle equipped with a transmission with an automatic shift function. When moving the shifter at a constant speed via an operating iron operated by an electric motor, it is possible to smoothly connect and disconnect each gear.
The displacement speed of the shifter is adjusted according to changes in the operating force applied to the shifter, and the reduction in the rotation speed of the power transmission gear for synchronization with the shifter can be suppressed. To provide an operation mechanism for a power take-off device in a specially equipped vehicle, which quickly raises the power take-off device until it balances the driving force of the gear, thereby preventing noise and damage to the tooth surfaces that occur when the shifter and the power transmission gear mesh. be.

[Means to solve the problem]

INDUSTRIAL APPLICABILITY The present invention is applied to a power extraction device for a specially equipped vehicle, which extracts power from an engine operating while the vehicle is stopped for use in a hydraulic actuator that enables the vehicle's equipment to carry out various operations.

Its characteristics are as shown in FIGS. 1 and 2, the engine 3 taken out from the transmission 4.
A power take-off gear 11 is fixed to an input shaft 2 which transmits power and rotates at all times, and a ring gear of the same diameter as the removable ring gear is movably attached to the input shaft 2 in the vicinity of the power take-off gear 11. 14 and a power transmission gear 15 are disposed, a shifter 16 is movable in the input shaft direction so as to be able to mesh with any of the gears at the same time, and an operating rod 7 is displaced to move the shifter 16. Annular gear 14
A fitting conical surface 14 that expands toward the power transmission gear 15 is provided on the inner surface of the
b is formed, and the power transmission gear 15 is provided with an output conical surface 15b that can be fitted to and removed from the fitted conical surface 14b. When moving the shifter 16 to engage the shifter 15, an electric motor 9 is provided which applies an operating force in the pulling direction to displace the operating rod 7 at a constant speed.

When the operating rod 7 is pulled by the electric motor 9, the shifter 1
6 and directly transmits the displacement of the operating rod 7 after the power storage limit, the shifter 16 is meshed with the ring gear 14, and the shifter 16 is completely meshed with the ring gear 14. When the engagement reaction force acting on the rod 7 suddenly decreases, the operating rod 7 is displaced at a constant speed.
The operating rod 7 is provided with a variable length buffer type force accumulating means 10 which releases the accumulated force to speed up the displacement of the operating rod 7.

As a result, the time from when the shifter 16 completes meshing with the annular gear 14 until it starts meshing with the power transmission gear 15 is shortened, and the synchronous rotational speed of the power transmission gear 15 is prevented from decreasing significantly during that time. This is what we have made possible.

The variable length buffer type force storage means 10 (see FIG. 3(a)) has a cylinder 10d, a piston 10a, and a piston rod tab, and has an electric motor that applies an operating force in the pulling direction to the piston rod 10b side. It is preferable that the motor 9 is connected and a compression spring 10c is interposed on the piston rod 10b side within the cylinder 10d.

As shown in FIG. 4, the variable length buffer type force storage means 10 includes an electric motor 9 which has a cylinder 10d, a piston 10a, and a piston rod fob, and which applies an operating force in the pulling direction to the piston rod 10b side. , and compressed gas 1 is connected to the piston rod 10b side in the cylinder 10d.
It is also possible to adopt a configuration in which Oe is enclosed.

[For production]

Power from the engine is transmitted via a transmission to a power extraction gear 11 fixed to an input shaft 2 of a power extraction device 1.
is transmitted. The shifter 16 is meshed only with the power take-off gear 11, and the shifter 16 is also rotating. When the electric motor 9 is driven in this state, the operating force in the pulling direction is applied to the operating rod 7 and the variable length buffer type force storage means 10.
[See Figure 3(a)]. The shifter 16 begins to move due to the displacement of the operating rod 7, and receives the operating force,
The shifter 16 begins to mesh with the ring gear 14.

The operating force increases during the engagement, but when the engagement reaction force exceeds a predetermined value, the variable length buffer type force storage means 1
0 starts accumulating force while absorbing the displacement of the operating rod 7, and at the same time suppresses movement of the shifter 16.

When the variable length buffer type power storage means 10 reaches the power storage limit,
From then on, the displacement of the operating rod 7 is directly transmitted to the shifter 16, the shifter 16 moves following the displacement of the operating port/end 7, and the shifter 16 is completely meshed with the annular gear 14. In other words, the time required for the shifter 16 and the ring gear 14 to complete their engagement is extended by the variable length shock absorbing force storage means IO.

During this meshing, the shifter 16 slightly moves the ring gear 14 toward the power transmission gear 15, so that the fitted conical surface 14b of the ring gear 14 does not completely contact the output conical surface 15b of the power transmission gear 15. is closely attached. Therefore, the power transmission gear 15 starts rotating with the rotation of the ring gear 14.

Even after this state, the operating rod 7 is displaced at a constant speed, and the shifter 16 further moves toward the power transmission gear 15. However, after the shifter 16 completely meshes with the ring gear 14, no force is needed to push the ring gear 14 into engagement, and the shifter 16 can also push the ring gear 14 toward the power transmission gear 15. do not have. Therefore, the meshing reaction force acting on the operating rod 7 sharply decreases after the meshing with the annular gear 14 is completed. As a result, the force accumulated in the variable length buffer type force storage means 10 is released, and the operating rod 7, which is being displaced at a constant speed, is accelerated. That is, the pulling force of the operating rod 7 and the variable length buffer type force storage means 10
The accumulated force acts on the shifter 16 in synergy, and the shifter 16 moves to the power transmission gear 15 in a short time. Time T until it starts meshing with the power transmission gear 15
2 (see FIG. 6(a)) is small.

When the shifter 16 and the annular gear 14 achieve complete meshing, the force with which the shifter 16 presses the annular gear 14 toward the power transmission gear 15 rapidly decreases, so that the annular gear 1
The adhesion force between the fitting conical surface 14b of No. 4 and the output conical surface 15b of the power transmission gear 15 is weakened, and the rotation of the power transmission gear 15 that has been rotating together begins to decrease. However, the time during which the close contact becomes weak is as short as Tt, and the rotational speed of the power transmission gear 15 that occurs during this period is not significantly reduced. In other words, the deviation in synchronous speed between the shifter 16 and the power transmission gear 15 is small. Therefore, the subsequent meshing between the shifter 16 and the power transmission gear 15 is smooth, and there is no noise or damage to the tooth surface caused by the meshing. Prevented.

When the shifter 16 starts to mesh with the power transmission gear 15 and the meshing becomes complete, the power transmission gear 15 rotates at a speed Ro (see FIG. 6(b)) that balances the driving force of the shifter 16, that is, the power take-off gear 11. The power then drives hydraulic pumps, etc.

As the above-mentioned variable length buffer type force storage means 10, the cylinder 1
Compression spring 10 on the piston rod lOb side in 0d
c is interposed, when the operating rod 7 receives a meshing reaction force greater than a predetermined value, the compression spring 10c starts to contract, and the displacement of the operating rod 7 is caused by the compression spring 10c.
absorbed by. While absorbing the displacement, the variable length buffering force storage means 10 suppresses the movement of the shifter 16,
Force is accumulated by the compression deformation of the compression spring 10c.

The point in time when the compression spring 10c is completely compressed is the power storage limit, and the subsequent displacement of the operating rod 7 is directly transmitted to the shifter 16.

When the shifter 16 is meshed with the ring gear 14, a meshing reaction force is generated, but after the shifter 16 is completely meshed, the meshing reaction force almost disappears, and at that point, the force accumulated in the compression spring 10c is released. It is added to the force displacing the operating rod 7.

Instead of such a compressing action of a spring, it is also possible to use the compressing action of air. In that case, compressed gas 10e may be sealed in the piston rod side tab in the cylinder 10d (see FIG. 4).

〔Effect of the invention〕

According to the present invention, the time required for the shifter to fully mesh with the ring gear is lengthened by absorbing the displacement of the operating rond by the variable length buffer type force storage means, while the time required for the shifter to fully mesh with the ring gear is increased. Until the shifter starts to mesh with the rear power transmission gear, the displacement of the operating iron is accelerated by releasing the force stored in the variable length buffer type force storage means, and the shifter and the power transmission gear start to mesh quickly. If the time between the shifter fully meshing with the ring gear and the time it starts to mesh with the power transmission gear is short, the rotation of the power transmission gear that rotates with the ring gear will decrease to a lesser extent, and the shifter will be connected to the power transmission gear. It is possible to reduce synchronization deviation when meshing. Therefore, the generation of gear noise and switching noise during meshing is reduced, and damage to the tooth surfaces is prevented.

〔Example〕

The present invention will be described in detail below with reference to the drawings. The power extraction device l shown in FIG. 1 has an input shaft 2 connected to a transmission 4 that transmits power from an engine 3, and is provided with an extraction shaft 6 that extracts the driving power of a hydraulic pump 5 that operates a hydraulic actuator by its rotation. It is being An operating rod 7 is attached that can be displaced to extract power from the human power shaft 2 to the extraction shaft 6 or to stop the extraction, and is connected to an electric motor 9 via a bell crank 8 to extract power from the passenger compartment or the like. The operating rod 7 can be displaced at a constant speed by mechanical operation based on a remote command.

The operating rod 7 is composed of a front rod 7A and a rear door B, with a piston 10a between them.

A variable length shock absorbing force storage means 1O having a built-in piston rod 10b and a compression spring 10C is interposed. The front rod 7A is connected to the base of the cylinder IOd, and the rear door B is connected to the piston rod tab.

FIG. 2 is a sectional view of the main part of the power take-off device 1. Inside the casing IA, there is a power take-off gear 11 having external teeth 11a, and two bearings 2 are connected to each other via a spline llb.
It is attached to the input shaft 2 supported by a and 2b.

On the input shaft 2, an intermediate gear 12 is movably provided adjacent to the power take-off gear 11 via a needle bearing 12a, and a take-out gear fixed to the take-out shaft 6 supported by two bearings 6a and 6b. It is engaged with 13.

Between the power take-off gear 11 and the intermediate gear 12, there is provided an annular gear 14 having external transmission teeth 14a that are concentric and have the same diameter as the power take-off gear 11, and the same gear specification is also provided on the side thereof. A power transmission gear 15 having external input teeth 15a is arranged. And power take-off gear 11. A cylindrical shifter 16 is provided that has shift internal teeth 16a that mesh with the annular gear 14 and the power transmission gear 15, and can move in the axial direction of the input shaft 2. In order to move this shifter 16, a front rod 7 is provided with a fitting member 17 shown by a two-dot chain line that engages with a recess 16b formed on the outer periphery.
The tip of A is also stored.

The casing IA is located at the part where the input shaft 2 passes through and the take-out shaft 6.
The lid member 1a covers the other end of the input shaft 2, and the lid member 1b covers one end of the input shaft 2. figure〕
are arranged.

The power take-off gear 11 has shift internal teeth 16 of the shifter 16.
As mentioned above, the external teeth 11a that mesh with the input shaft 2 are carved, and the input shaft 2 is constantly rotating when the engine 3 is operated. If the shifter 16 is moved as shown by the two-dot chain line, the shifter 16 meshes only with the power take-off gear 11 and constantly rotates.

A fitting conical surface 14b that expands toward the power transmission gear 15 is formed on the inner surface of the annular gear 14, and the transmission external tooth 14 on the outer surface
The tooth width of a is gradually cut off to become approximately triangular in plan view at the end on the power extraction gear ll side. On the other hand, the shift internal gear 16a of the shifter 16 is also cut off in a triangular shape on the side facing the ring gear 14, so that when the shifter 16 is moved toward the ring gear 16,
The rotating internal shift teeth 16a are designed so that the initial engagement with the non-rotating ring gear 14 is smooth.

An output conical surface 15b that can be fitted into and removed from the above-mentioned fitting conical surface 14b of the circular gear 14 is engaged with the inner surface of the power transmission gear 15, and the tooth width of the input external teeth 15a on the outer surface is equal to that of the circular gear 14. The side edges are gradually cut off to make it approximately triangular in plan view.

Therefore, the shift inner teeth 16a are cut off into a triangular shape.
When the shifter 16 is moved to the power transmission gear 15, the rotating shifter 16 can be smoothly fitted in at the beginning of meshing with the slowly rotating power transmission gear 15. Note that the annular gear 14 is made of a material such as brass, which is different from other gears made of steel, and the output conical surface 15 is formed on the fitted conical surface 14b.
This facilitates close contact with b. Further, serrations 14c are formed on the surface of the conical surface 14b to be fitted, so that the frictional force generated when the conical surface 14b comes into close contact with the output conical surface 15b can be further enhanced.

The above-mentioned power transmission gear 15 is provided with internal teeth 15c,
The intermediate gear 12 is meshed with engagement external teeth 12c formed on a small diameter boss portion 12b that protrudes toward the power transmission gear 15 side. As a result, the power transmission gear 15 has a structure that is integrated with the intermediate gear 12 that rotates the extraction shaft 6. Note that the power transmission gear 15 and the intermediate gear 12 may be integrated in advance.

FIG. 3(a) shows an example of a variable length buffer type power storage means 10 interposed in the operating rod 7, in which the rear door B is pulled in the direction of the arrow X by the electric motor 9 (see FIG. 1). , when the shifter 16 meshes with the ring gear 14, the compression spring 10c
has been reduced in size, absorbing the displacement of the rear door B and accumulating power. During this time, the displacement of the front rod 7A is interrupted and the movement of the shifter 16 is suppressed. When the compression spring 10c contracts as shown in FIG. 3(b) and reaches its storage limit, the displacement of the rear door B is directly transmitted to the front rod 7A, allowing the shifter 16 to resume movement. This movement causes the shifter 16 to mesh with the annular gear 14, and when the meshing reaction force acting on the operating rod 7 suddenly decreases for the reason described later, the compression spring 10c engages the operating rod 7, which is displaced at a constant speed. The stored force can be released and the displacement of the operating rod 7 can be accelerated.

Note that in FIG. 2, when the operating rod 7 is pulled to the illustrated position, the shifter 16 has been moved to the power transmission gear 15 as shown by the solid line, and the front end 7a of the operating rod 7 has been moved.
is positioned slightly into the recessed hole IC formed in the casing IA, and the ball-shaped blocking member 19 biased by the spring 18 fits into the first ring groove 7b, and no force is applied to the operating rod 7. For example, the insert member 17 is retained in that position. On the other hand, when the operating rod 7 is pushed in by reversing the electric motor 9, the front end 7a is brought into a deep position in the recessed hole 1ε, and the blocking member 19 is pushed into the second ring groove 7c.
, so that the shifter 16 remains in a position where it meshes only with the power take-off gear 11, as shown by the two-dot chain line.

According to the power extraction device 1 having such a configuration, the hydraulic pump 5 that supplies hydraulic oil to actuators for various operations mounted on a specially equipped vehicle can be driven by the power extracted from the transmission 4, and further, When extracting power,
The shifter 16 and the power transmission gear 15 are smoothly engaged by the operation of the variable length buffer type power storage means 10. The temporal changes in operation of this operating mechanism are shown in Fig. 6 (C) above.
Figure 6 (a) and (d) are shown overlappingly.
This will be explained with reference to b).

After the vehicle is stopped, the range selector lever of the automatic transmission is placed in the P range, and the power from the idling engine 3 is transmitted to the input shaft 2 via the transmission 4, and the power take-off gear 11 is It rotates (see line A in Figure 6(b)).

At this time, the shifter 16 is meshed only with the power take-off gear 11 as shown in FIG.
6 is also rotating.

When the electric motor 9 is started by a command operation in the passenger compartment, an operating force in the pulling direction of the arrow X acts on the operation port/end 7 via the bell crank 8, As a result, the front rod 7A is displaced.

Due to this displacement, the shifter 16 is moved toward the ring gear 14 as shown by the two-dot chain line in FIG. 5(a) [see line B in FIG. 6(a)]. Shifter 16 is ring gear 1
A large force is not required until reaching the external transmission tooth 14a of No. 4, and during that movement, the operating force in the pulling direction is gradually increased by the electric motor 9 [see line 0 in FIG. 6(a)]. ,
The blocking member 19 fitted into the second ring groove 7C (see FIG. 2) retreats against the elastic force of the spring 18, and the blocking member 19 is released.

The shifter 16 begins to mesh with the annular gear 14, and the annular gear 14 starts rotating [see the arrowed part in Fig. 6 (b)]
. The rotating internal shift teeth 16a do not immediately mesh with the external transmission teeth 14a of the ring gear 14, and the rear end of the triangularly pointed shift internal teeth 16a pushes the front end of the similarly pointed triangular external transmission teeth 14a. The shifter 16 moves toward the annular gear 14 in such a manner that it separates. Therefore, sufficient force is transmitted to the shifter 16 via the operating rod 7 so that the transmission outer teeth 14a push the shift inner teeth 16a apart.

This pushing amount acts on the front rod 7A as a reaction force due to the engagement between the transmission outer teeth 14a and the shift inner teeth 16a.

This meshing reaction force is generated between the shift inner teeth 16a and the transmission outer teeth 14.
It becomes larger as the engagement with a progresses. However, before the engagement reaction force becomes large, the compression spring 10C of the variable length shock absorbing force storage means 10 begins to compress as it is sandwiched between the piston loa and the rear end wall of the cylinder 10d. During this time, the operating force gradually increases [see arrow E in Figure 6(a)]
, the displacement of the rear door B, which is displaced by the pulling force at a constant speed, is absorbed. During this time, the pulling force of the rear door B is not transmitted to the front rod 7A, so the shifter 16 is not moved [see line F in FIG. 6(a)].

The shifter 16 and the ring gear 14 will continue to be in a state where they are not fully engaged, but the rotation of the ring gear 14 will gradually increase in speed [see line 0 in FIG. 6(b)] ]
. During this time, the ring gear 14 is being pushed toward the power transmission gear 15, and the fitted conical surface 14b is
Although not completely in contact with the output conical surface 15b of No. 5, Therefore, the power transmission gear 15, which had not been rotating, also starts rotating [see line F in FIG. 6(b)]. Shift internal teeth 1
When the compression spring 10c contracts due to the displacement of the rear Rondo door B and reaches its storage capacity limit without sufficient engagement between the rear Rondo door B and the external transmission tooth 14a, the subsequent displacement of the rear Rondo door B is directly transmitted to the front rod 7A. [See line 1 in FIG. 6(a)]. Therefore, at that point, the shifter 16 starts moving again, and the shifter 16 is deeply engaged with the ring gear 14. During this time, the frictional force between the shift internal teeth 16a and the transmission external teeth 14a reaches a peak [see arrow 3 in FIG. are in a meshed state where they completely face each other [see the arrows in FIGS. 6(a) and 6(b)].

Note that during this time, the fitting conical surface 14b is the output conical surface 15b.
The rotation of the power transmission gear 15 is further accelerated.

However, when the shifter 16 and the annular gear 14 are completely engaged, the pushing force of the shifter 16 against the annular gear 14 decreases rapidly when the side surfaces of both teeth face each other, and the operating force of the shifter 16 decreases. Refer to the line part in Figure 6 (a)]
. At the same time, the close contact between the fitting conical surface 14b and the output conical surface 15b loosens, so the force for rotating the power transmission gear 15 decreases and its rotation begins to decelerate [Fig. 6 (1)
))). As the engagement reaction force acting on the shifter 16 is reduced, the compressed spring 10c, which had been contracted within the variable length buffer type force storage means 10, is restored and its stored force is released. This force adds weight to the pulling force acting on the operating rod 7 by the electric motor 9, increasing the operating force (see line N in FIG. 6(a)).

A large force generated by the synergy of both forces acts on the shifter 16, and as shown in FIG. The time T2 (see FIG. 6(a)) until the input external tooth 15a starts to mesh with the input external tooth 15a is shorter than the time T1 (see FIG. 6(C)) described in the related art section. When the shifter 16 starts to mesh with the input external teeth 15a [see arrow N in FIGS. 6(a) and 6(b)], the power transmission gear 15 begins to be actively rotated by the shifter 16 [FIG. 6(c)] (see part 2 of the line), but the rotation of the power transmission gear 15 only drops to R during the short time Tt mentioned above. That is, the amount of decrease in the rotational speed is as small as Rb, and the synchronization difference at the time when the shifter 16 starts to mesh with the power transmission gear 15 is Rc as explained in FIG. 6(d).
The Rd is significantly lower than that of the above. Therefore, the meshing between the shift internal teeth 16a and the input external teeth 15a is smooth, and the time it takes for the shifter 16 to move and reach complete meshing with the power transmission gear 15 (see FIG. 5(C)) is also somewhat shortened. At this time, gear noise and switching noise are significantly reduced. The impact when the shift internal teeth 16a and the input external teeth 15a start meshing is also reduced, and the tooth surfaces are not damaged.

When stopping the drive of the hydraulic pump, the electric motor 9 is reversed and a pushing force is applied to the operating rod 7. Since the compression spring 10c has already been restored, the piston 10a is in contact with the front end wall of the cylinder 10d, and the displacement of the rear Ron door B is immediately transmitted to the front Ron door A. Therefore, the shifter 16, which is meshed and rotates at the same speed, is easily detached from the power transmission gear 15, and when the shifter 16 moves back, the fitted conical surface 14b becomes the output conical surface 1.
5b, it is easily disengaged from the annular gear 14 which is meshed and rotating at the same speed, and is returned to the state of meshing only with the power take-off gear 11.

Compression spring 10c in variable length buffer type force storage means 10
remains restored within the cylinder 10d, and when the electric motor 9 is rotated normally again, the above-described power extraction operation can be performed.

The above description is based on an example in which a spring tube is used as the variable length buffer type force storage means 10, but as shown in FIG. 4, a compressed gas 10e may be enclosed in place of the spring 10c. If the gas pressure is increased in advance, the displacement of the rear rond door B will be controlled by the front rond door A until the specified compression is applied.
When that pressure is reached, it begins to contract in the same way as the compression spring 10c described above, and when the meshing reaction force acting on the front rod 7A becomes i, i, the compression force becomes It is released through a piston 10a that moves while being kept airtight by a piston ring 10f,
The speed increasing function can be performed in synergy with the displacement operation of the operating rod 7. In addition, in order to smoothly move the piston 10a, a suction/discharge port 10g is provided in the piston side chamber.

As explained in detail above, compared to the conventional power take-off device, the time required for the shifter 16 to complete meshing with the annular gear 14 is T3 (see FIG. 6(C) and (φ)).
to time T4 (see FIGS. 6(a) and 6(b)) to lengthen the initial entrainment time of the power transmission gear 15.
After the meshing with the shifter 16 and the power transmission gear 15 is completed, the operating rod 7 having a constant displacement speed releases the stored power of the variable length buffer type power storage means IO to increase the speed, and the shifter 16 and the power transmission gear 15 start to mesh with each other. Time T, [Figure 6 (C)
and (d)] to the time 'rz (see FIGS. 6(a) and (b)) to reduce the time during which the adhesion between the fitting conical surface 14b and the output conical surface 15b decreases, The degree of decrease in the accompanying rotation speed of the power transmission gear 15 is prevented from becoming significant.As a result, after the electric motor 9 is started, the shifter 16 meshes with the power transmission gear I5, and the output for transmitting power to a hydraulic pump or the like Even though the total time until the gear 13 is rotated is the same or slightly shorter, the power transmission gear 15 can be driven smoothly without gear noise or the like.

Although the above description has been made regarding a specially equipped vehicle equipped with an automatic transmission, the present invention can also be applied to a vehicle equipped with a transmission that does not have such an automatic transmission function.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the operating mechanism for operating the power take-off device of the present invention, FIG. 2 is a cross-sectional view of the main parts of the power take-off device, and FIG.
Figures (a) and (b) are explanatory diagrams of the structure and operation of a spring cylinder, which is a variable length buffer type force storage means, and Figure 4 is an explanatory diagram of the operation of a compressed gas cylinder, which is a different variable length buffer type force storage unit. , FIGS. 5(a) to 5(C) are explanatory diagrams of the meshing operation of the shifter, the annular gear, and the power transmission gear, and FIGS. 6(a) and (b) are temporal changes in the operation of the operating mechanism in the present invention. Figure 6 (C
) and (d) are graphs explaining temporal changes in operation of the conventional operating mechanism. ■-power take-off device, 2--input shaft, 3--engine, 4--transmission, 7--operating rod,
9 electric motor, 10--variable length buffer type power storage means, 1
0a...-piston, 10b...-piston rod,
IOC...compression spring, 10d- cylinder, 1
0e--Compressed gas, 11--Power take-off gear, 14-Annular gear, 14a--Transmission external tooth, 14b--Fitting conical surface, 15--Power transmission gear, 15a--Manual external tooth, 15b
-Output conical surface, 16-Shifter 16a.-Shift internal teeth.

Claims (3)

[Claims] (1) A power take-off gear is fixed to an input shaft that is constantly rotating by transmitting the engine power taken out from the transmission, and a concentric gear that is movably attached to the input shaft in close proximity to the power take-off gear An annular gear and a power transmission gear of the same diameter are arranged, a shifter is movable in the direction of the input shaft so that it can mesh with any of the gears at the same time, and an operating rod is displaced to move the shifter. A synchronizer is provided, wherein the inner surface of the annular gear is formed with a fitting conical surface that extends toward the power take-off gear, and the power transmission gear is formed with an output conical surface that can be fitted and removed from the fitting conical surface. In a power extraction device for a specially equipped vehicle having a mechanism, when moving the shifter to mesh with the annular gear and the power transmission gear, an electric motor applies an operating force in a pulling direction to displace the operating rod at a constant speed. is provided, and when the operating rod is pulled by the electric motor, it accumulates force while absorbing the displacement of the operating rod from the time when it receives a meshing reaction force of a predetermined amount or more, and also suppresses the movement of the shifter, thereby increasing the energy storage limit. After that, the displacement of the operating rod is directly transmitted, and the shifter is meshed with the ring gear, and the shifter is completely meshed with the ring gear, so that the meshing reaction force acting on the operating rod suddenly decreases. A variable length buffer type force storage means is interposed in the operating rod to release the stored force to the operating rod which is displaced at a constant speed to accelerate the displacement of the operating rod, and the shifter completes meshing with the ring gear. A power extraction device for a specially equipped vehicle, characterized in that the time required for the gear to start meshing with the power transmission gear after the transmission of the gear is reduced, and the synchronous rotational speed of the power transmission gear is prevented from significantly decreasing during that time. Operating mechanism of the device. (2) The variable length buffer type force storage means has a cylinder, a piston, and a piston rod, and the electric motor that applies an operating force in a pulling direction is connected to the piston rod side, and the piston rod in the cylinder 2. The operating mechanism for a power take-off device in a specially equipped vehicle according to claim 1, further comprising a compression spring interposed on the side thereof. (3) The variable length buffer type force storage means has a cylinder, a piston, and a piston rod, and the electric motor that applies an operating force in a pulling direction is connected to the piston rod side, and the piston rod side in the cylinder 2. The operating mechanism for a power take-off device in a specially equipped vehicle according to claim 1, wherein compressed gas is sealed in the operating mechanism.