JPS641186Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a cab lifting device.

BACKGROUND OF THE INVENTION Some large automobiles with an engine mounted under the driver's cab are equipped with a driver's cab lifting device for lifting the driver's cab when inspecting or repairing the engine.

Conventionally, there are mechanical and hydraulic types of these cab lifting devices, each of which has advantages and disadvantages, and the present invention relates to the mechanical type.

In a mechanical cab lifting device, when the device lifts the cab or lowers the cab, if the load is too large, the motor in the cab lifting device can automatically stop. Must be familiar.

To deal with such problems, conventionally a detector is provided on the worm of the worm gear interposed in the power transmission path of the cab lifting device, and the detector detects the movement of the worm in the axial direction. The overload condition was detected by

In other words, the structure is such that the axial direction of the worm is supported by a spring, and when a large load torque is applied to the worm, the worm moves in a direction that compresses the spring in proportion to the load torque. When the value of the movement exceeds a predetermined value, the worm contacts the limit switch to detect an overload.

However, in such a conventional configuration, the direction of the load torque is opposite when lifting the cab and when lowering the cab.
In order to detect overload both during lifting and lowering, the worm is configured to move in both directions, thereby providing a limit switch for detecting overload during lifting and a limit switch for detecting overload during lowering. It would be required to install both limit switches to detect the load.

This not only increases the size of the detection device, but also requires the use of two limit switches.

An object of the present invention is to provide a driver's cab lifting device that solves the above-mentioned problems.

The present invention will be described below based on examples.

FIG. 1 shows a side sectional view of a driver's cab lifting device as an embodiment of the present invention, FIG. 2 shows a cross section in FIG. 1, and FIG. 4 shows an enlarged view of the one-way brake device 3 in FIG. 3, FIG. 4 shows a cross section of the brake plate 3h in FIG. 3, and FIG. This is what is shown.

In FIG. 1, a straight-tooth bevel gear 1b is fitted to the output shaft 1a of a motor 1 to enable torque transmission and to slide in the axial direction, and a spring 1c is fitted to the output shaft 1a of a motor 1.
urges the bevel gear 1b to the right, the protrusion 1d is fixed to the bevel gear 1b, and a limit switch 4a as a detector is fixed to the left of the protrusion 1d.

Straight-tooth bevel gear 2a gear-engaged with bevel gear 1b
is fitted onto the drive shaft 2, the drive shaft 2 is pivotally supported on the casing 4, and the drive shaft 2 is connected via the one-way brake device 3, the worm 3a and the worm wheel 5b,
It is configured to rotationally drive a screw 5c fitted into a worm wheel 5b.

Here, the worm 3a and the worm wheel 5b
constitutes a reduction gear by engaging gears.

The screw 5c pivotally supported in the casing 4 is a nut 5d.
The pipe 5e is screwed into the nut 5d.
A joint 5a is fixed to the end of the vehicle, and the joint 5a is configured to be connected to a part of the driver's cab (not shown).

As shown in detail in FIG. 3, the one-way brake device 3 in FIG. 1 has a disk 3e spline-fitted to the drive shaft 2, and a sleeve 3m interposed between the disk 3e and the bevel gear 2a. In this state, the bearing 3f is fitted to the drive shaft 2, the disc-shaped friction plates 3g and 3j and the brake plate 3h are fitted to the bearing 3f, and the clutch disk 3b is fitted to the drive shaft 2.
The female thread 3c cut into the drive shaft 2 threadably engages with the male thread 3d cut into the drive shaft 2, and this threaded engagement occurs when the male thread 3d rotates in the direction of arrow a relative to the female thread 3c. , the clutch disc 3b moves in the direction c, and the male thread 3d becomes the female thread 3c.
When the clutch disk 3 rotates in the direction opposite to the arrow a relative to the
b is in a relationship that moves in the b direction.

Moreover, the brake plate 3h is as shown in FIG.
Allows free rotation when rotating in the direction of arrow f,
When trying to rotate in the direction opposite to arrow f, tooth 3
The pawl 3p is engaged with the pawl 3p to prevent its rotation.

In addition, the pawl 3p is pivotally connected to the pin 3n, and the pawl 3p
The structure is such that the force of the spring 3q is applied to the spring 3q.

In the configuration of the embodiment of the present invention described above,
The effect will be explained below.

When the motor 1 rotates the output shaft 1a clockwise when viewed from the right side of FIG. Then, the clutch disc 3b moves in the direction of arrow b, and the clutch disc 3b and disc 3e move toward the friction plate 3j,
The brake plate 3h and the friction plate 3g are integrally tightened, and the one-way brake device 3 is integrated, so that the rotation of the drive shaft 2 drives the worm 3a.

In addition, since the rotational direction of the brake plate 3h at this time is the f direction in FIG. 4, the brake plate 3h is not restrained by the pawl 3p and is allowed to rotate, and the one-way brake device 3 is also integrated. It is now in a state where it can be rotated.

Therefore, in this state, the rotation of the drive shaft 2 is caused by the disk 3e, the friction plate 3g, the brake plate 3h,
The worm 3a is driven in the direction opposite to the arrow a through the friction plate 3j and the clutch disk 3b, and the driving of the worm 3a rotates the worm wheel 5b clockwise when viewed from the left side in FIG.

When the worm wheel 5b is driven clockwise in this way, the screw 5c fixed to the worm wheel 5b also rotates together with the worm wheel 5b, so the nut 5d is moved upward ( (to the left in Fig. 2), and the upward movement of the nut 5d is caused by the pipe 5e.
Then, a driver's cab (not shown) is lifted upward via the joint 5a.

When lifting the driver's cab, if motor 1 is stopped, the weight of the driver's cab will cause the nut 5 to
d is about to be pushed down, but at this time, the one-way brake device 3 interlocks with the pushing down and applies a brake to the pushing down.

The braking action will be explained below.

When the nut 5d is pushed down by the weight of the driver's cab, the force to push it down is exerted by the threaded engagement between the nut 5d and the screw 5c.
c is rotated counterclockwise when viewed from the left in FIG. It will be rotated in the circumferential direction (arrow a direction).

As mentioned above, this is achieved by the clutch disk 3 due to the threaded engagement between the female thread 3c and the male thread 3d.
b will move in the direction b, and as a result, the disc 3e and clutch disc 3b will tighten the friction plate 3g, brake plate 3h, and friction plate 3j, and the one-way brake device 3 will move toward the driver's cab. One-way brake device 3 as well as when lifting
to integrate.

However, when the clutch disk 3b is rotated by the weight of the driver's cab, the direction of rotation of the clutch disk 3b is opposite to the direction of rotation when lifting the driver's cab. This is prevented by a freewheel mechanism consisting of teeth 3i and pawls 3p.

That is, when the clutch disk 3b tries to rotate together with the brake plate 3h in the direction of the arrow a, the brake plate 3h tries to rotate in the opposite direction to the direction of the arrow f in FIG. 3p is a tooth 3i on the brake plate 3h
The brake plate 3h is stopped from rotating.

When lowering the driver's cab in response to the above operation, the motor 1 may be driven in the opposite direction to the direction of lifting the driver's cab as described below.

When the motor 1 is driven in the opposite direction to when lifting the driver's cab, the bevel gear 2a is rotated in the direction of arrow a, and the male screw 3d is also rotated in the direction of arrow a. The clutch disk 3b is moved in the direction of arrow c until it comes into contact with the sleeve 3k by the threaded engagement of the female screw 3c with the female screw 3c, and thereby the brake plate 3h is moved between the disk 3e and the clutch disk 3b as shown in FIG. gaps d and e are formed between the drive system of the drive shaft 2 and the brake plate 3h.
This will cause the engagement to be severed.

Therefore, in this case, even if the clutch disk 3b rotates in the direction of the arrow a, the rotation will not be blocked by the pawl 3p.

When the clutch disk 3b, that is, the worm 3a rotates in the direction of the arrow a, the worm 3
a is a screw 5c via a worm wheel 5b,
It is to be rotated counterclockwise when viewed from the left side of Fig. 2, and the rotation is performed by screw 5c and nut 5.
d by threading the nut 5d downward (second
(to the right in the figure), and this movement lowers the driver's cab downward via the pipe 5e and the joint 5a.

In the above operation, if the weight of the driver's cab becomes very heavy, or if a failure occurs in the power transmission path from the motor 1 to the joint 5a and the load torque of the motor 1 increases, the bevel gear 1b The protrusion 1d acts on the limit switch 4a to stop the operation of the motor 1. The effect will be explained below.

When the load torque of the output shaft 1a increases abnormally,
Since the bevel gear 1b is engaged with the bevel gear 2a as a bevel gear, the reaction force of the abnormal torque generated in the gear engagement causes the bevel gear 1b to move to the left against the biasing force of the spring 1c.

When this transition occurs, the protrusion 1d comes into contact with the contact of the limit switch 4a, and the limit switch 4a
senses the contact and closes the supply of energy (for example, electrical energy) to the motor 1, thereby stopping the rotation of the motor 1 and ensuring the safety of the entire device.

In addition, when motor 1 lifts the driver's cab,
When lowering the driver's cab, the direction of the torque generated on the output shaft 1a is reversed.

However, since the gear engagement between the bevel gear 1b and the bevel gear 2a is a straight-tooth gear engagement, the output shaft 1a is When the torque becomes overloaded, the bevel gear 1b is moved to the left in FIG. 1 by the tooth surface of its immediate tooth.

Therefore, the limit switch 4a, which is a single detector, can detect overloads occurring in the drive system whether the cab is being raised or lowered. Become.

In the above embodiment, the overload occurring in the drive system is detected by the leftward movement of the bevel gear 1b. It will be easy to understand from the above explanation that 2a also makes this possible.

However, if the above-mentioned overload is detected at the output shaft 1a of the motor 1, even if a condition that causes an overload occurs in any part of the entire drive path from the motor 1 to the driver's cab, the drive It has the advantage that overload can be detected at the entrance of the route.

In addition, since the rotation of the drive shaft 2 is decelerated through a reduction gear consisting of a worm 3a and a worm wheel 5b, and then transmitted to the screw 5c, the rotation of the drive shaft 2 is transmitted to the screw 5c. The torque in 2) is smaller than the torque in the screw 5c.

Therefore, the torque capacity of the bevel gear 2a and the bevel gear 1b between the reduction gear and the motor 1 only needs to have a small value.
becomes smaller, and as a result, the movement of the bevel gear 1b to the left when an overload occurs in the drive system is as follows:
The inertial force generated in the bevel gear 1b is reduced, increasing the responsiveness of its transition.

Further, in the above embodiment, the gear engagement consisting of the bevel gear 1b and the bevel gear 2a has a reduction ratio of approximately 1:1, but this relationship further reduces the rotation of the output shaft 1a. It is also possible to adopt a configuration in which power is transmitted from the output shaft 1a to the drive shaft 2.

In this case, since the gear engagement consisting of bevel gears 1b and 2a also becomes a reduction gear, the torque at the output shaft 1a becomes even smaller than the torque at the drive shaft 2, making the bevel gear 1b even smaller. I can do it.

As is clear from the above description, in the driver's cab lifting device according to the present invention, the rod-shaped screw 5c is rotatably supported on the casing 4 so as to rotate around the axis of the screw, and the screw 5c includes the following: The nut 5d is threadedly engaged, and one end of the nut 5d in the threaded axial direction has a joint 5a connected to a part of the driver's cab of the automobile.
and the rotational power from the motor 1 drives the screw 5c through a gear train consisting of gears engaged with the bevel gears 1b and 2a. In the above configuration, the gears of the bevel gears 1b and 2a The engagement consists of a gear engagement of a straight bevel gear, and in the gear engagement, one of the bevel gears 1b is capable of transmitting torque to one rotating shaft 1a that transmits the rotational power. and are fitted together so as to be slidable in the axial direction, and the one bevel gear 1b is fitted to a mating gear with which the one bevel gear engages in the axial direction of the one rotating shaft 1a. A biasing force is applied by a spring 1c in the direction of the bevel gear 2a, a projection 1d is fixed to the one bevel gear 1b, and in the direction in which the projection 1d moves in the axial direction of the one rotating shaft 1a, The detector 4a is fixedly installed, and the relationship between the protrusion 1d and the detector 4a is as follows: a: The protrusion 1d moves in a direction that resists the spring biasing force, and the protrusion 1d is at the position of the detector 4a. When the protrusion 1d reaches the position, the detector 4a detects the movement of the protrusion 1d, thereby stopping the drive of the motor 1; b: The protrusion 1d is moved to the side of the detector 4a by the spring biasing force When the protrusion 1d is separated from the detector 4a by moving toward the partner bevel gear 2a, the detector 4
Since a is such that the motor 1 is set in a state where it can drive the first rotating shaft 1a, the effect is as follows.

1 The first bevel gear that detects the overload condition has a straight-toothed bevel gear configuration, so whether the driver's cab is raised or lowered, the overload is detected. At this time, the direction in which one bevel gear moves from the reaction force is in the same direction toward the detector.

Therefore, a single detector can detect overloads in all operations.

2. A reduction gear is interposed between the screw 5c and the output shaft 1a of the motor, and the reduction gear and the output shaft 1a
When a gear train consisting of one bevel gear is interposed in a part of the drive system where the torque of The first bevel gear is small and lightweight.

Therefore, the inertial force of the first bevel gear when the first bevel gear moves toward the detector during an overload is small, and the overload detection response is good. and the motor will be protected immediately.

3. When the first bevel gear is installed directly on the output shaft of the motor, the detector detects the overload of the drive system at the entrance of the drive path, so the All overloads can be detected no matter where the cause of the overload occurs in any part of the drive train path.

[Brief explanation of the drawing]

FIG. 1 shows a side sectional view of a driver's cab lifting device as an embodiment of the present invention, FIG. 2 shows a cross-sectional view of FIG. 1, and FIG. , is an enlarged view of the one-way brake device 3 in FIG. 1, FIG. 4 is a sectional view of the brake plate 3h portion in FIG. 3, and FIG. 5 is an enlarged view of the one-way brake device 3 in FIG. FIG. The symbols used in the examples are as follows. 1...Motor, 1a...Output shaft, 1b...Bevel gear, 1c...Spring, 1d...Protrusion, 2...
Drive shaft, 2a...Bevel gear, 2b and 2c...Bearing, 3...One-way brake device, 3a...Worm, 3b...Clutch disk, 3c...Female thread, 3d...Male thread, 3e...Disk, 3f...
...bearing, 3g and 3j...friction plate, 3h...brake plate, 3i...teeth, 3k and 3m...sleeve, 3n...pin, 3p...pawl, 3q...spring, 4...casing, 4a ……Detector,
5... Extension device, 5a... Joint, 5b... Worm wheel, 5c... Screw, 5d... Nut, 5
e...pipe, 5f and 5g...bearing.

Claims (1)

[Claims for Utility Model Registration] 1. A rod-shaped screw is pivotally supported in a casing to rotate around the axis of the screw, a nut is threadedly engaged with the screw, and the screw shaft of the nut is At one end of the direction, a joint connected to a part of the driver's cab of the automobile is fixed, and the rotational power from the motor drives the screw through a gear train consisting of gear engagement of bevel gears. In the above configuration, the gear engagement of the bevel gear is a gear engagement of a straight bevel gear, and in the gear engagement, one of the bevel gears is one of the bevel gears that transmits the rotational power. The one bevel gear is fitted to the rotating shaft to enable torque transmission and to allow sliding in the axial direction of the rotating shaft, and the one bevel gear is engaged with the rotating shaft in the axial direction of the rotating shaft. A biasing force is applied by a spring in the direction of the bevel gear on the other side, and a protrusion is fixed to the first bevel gear, and in the direction in which the protrusion moves in the axial direction of the first rotating shaft, there is a detection force. the detector is fixedly installed, and the relationship between the protrusion and the detector is as follows: a: When the protrusion moves in a direction that resists the spring biasing force and the protrusion reaches the position of the detector, the detector detects the transition of the protrusion, thereby stopping the drive of the motor; b: the protrusion is transferred from the detector side to the mating bevel gear side by the spring biasing force; and, when the protrusion is detached from the detector, the detector is set in a state in which the motor can drive the one rotating shaft. Lifting equipment. 2. The drive path through which the motor drives the screw consists of a drive path in which a reducer is interposed, and a gear train consisting of gear engagement of bevel gears is interposed in the drive path between the motor and the reducer. A driver's cab lifting device as set forth in claim 1 of the utility model registration claim. 3. The driver's cab lifting device according to claim 1 or 2, wherein the first rotating shaft is the output shaft of a motor.