JPH0134828B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cab-lifting device for a cab-over type vehicle, which is required when the engine room of the vehicle is inspected or repaired.

In cab-over type automobiles, the driver's cab is provided above the engine room, so the driver's cab must be lifted up when inspecting or repairing the engine room.

Therefore, one of the conventional cab lifting devices is to use a hydraulic cylinder.
In the case of this method, when the driver's cab is set to a normal state and the vehicle is in a running state, the hydraulic cylinder directly receives vertical vibrations in the driver's cab, which deteriorates the ride comfort of the vehicle. You will end up letting it happen.

To solve this problem, so-called lost motion (lost motion) has traditionally been applied to the hydraulic cylinder.
However, this configuration is complicated and expensive.

On the other hand, there is a method of mechanically disconnecting the driver's cab from the hydraulic cylinder to perform the lost motion, but this conventional method involves fitting a pin orthogonally to the piston rod of the hydraulic cylinder. Since the pin is configured to selectively lock into or disengage from an arcuate groove provided in the driver's cab, the piston rod rotates around the rod axis to ensure that the pin enters the groove in its proper position. There is the trouble of having to provide a detent to prevent this from happening, and since the contact between the groove and the pin is a line contact, countermeasures against stress on the contact surface become a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a driver's cab lifting device for an automobile that eliminates the above-mentioned problems.

To explain the present invention based on an embodiment, FIG. 1 shows a schematic side view of a driver's cab lifting device according to an embodiment of the present invention when it is installed in an automobile. 2 shows a cross-sectional view of the support 3 in FIG. 1, and FIG. 3 shows a cross-sectional view of the support 3 in FIG. However, in FIGS. 2 and 3, the piston rod 5 (hereinafter simply referred to as the rod) shows a state in which it is most retracted toward the hydraulic actuator 4, and in FIG. 4, the piston rod 5 from the state in FIG. It shows that he is holding up 5.

As shown in FIG. 1, the cab lifting device according to the present invention is composed of a hydraulic actuator 4, a rod 5 in the hydraulic actuator 4, a support 3, and a switching valve for operating the hydraulic actuator 4. In Figure 1, illustration of the switching valve is omitted for convenience of explanation.

In the embodiment shown in FIG. 1, the axial end 4a of the hydraulic actuator is pivotally connected to the chassis 2 of the automobile, and the support 3 is fixed to the driver's cab 1. In such a configuration, the rod 5 When the driver's cab 1 is extended upward, the driver's cab 1 can be tilted around a fulcrum pivoted in front of the chassis 2, as shown in FIG.

The support 3 includes a main body 3j, holders 3a and 3.
A pair of holders 3a and 3d, which are made up of d and rocking body 3b and are fixed to main body 3j, form common female spherical surfaces 3e and 3e with 3h as the center, and female spherical surfaces 3e and 3e are A hemispherical rocking body 3b consisting of a male spherical surface 3i is sandwiched so that it can swing and slide,
The receiving surface 3g of the rocking body 3b is located at the center 3h.
It is located in the lower part.

A rod 5 is inserted into the hole 3c made in the rocking body 3b.
are fitted to allow sliding movement in the axial direction, and the rod 5
The abutment member 5a is firmly attached to the abutment member 5a, and the back surface 5b of the abutment member 5a goes around the outer circumferential direction of the rod 5 to form a male spherical surface, and the curvature of the male spherical surface is the same as that of the female spherical surface 3.
It has the same curvature as e and 3e.

To explain its operation in the above configuration, in the state shown in Figs. 2 and 3, that is, the state in which the rod 5 is retracted the shortest, the driver's cab is returned to the position where the car is ready to be driven. In this state, when the car is driven, the driver's cab 1 generally vibrates relative to the chassis 2, but in this case, the support 3 fixed to the driver's cab 1 is rotated by the rod at the hole 3c. 5, and the riding comfort caused by the vibration is reduced by an independent device including a shock absorber structure (not shown). It can be made comfortable by attenuating it.

When inspecting or repairing the engine, etc. located at the bottom of the driver's cab 1 from the above-mentioned normal driving position, when the hydraulic actuator 4 is activated and the rod 5 is extended, the abutting material 5 on the rod 5
a passes through the groove 3f, the contact surface 5c of the contact member 5a contacts the receiving surface 3g, and when the rod 5 further extends from the contact state, the rod 5 touches the contact member. 5a, rocking body 3b, supports 3a, 3d
Then, the driver's cab 1 is lifted up via the main body 3j.

In this way, in the process of the rod 5 lifting the driver's cab 1, the center of gravity of the driver's cab 1 moves counterclockwise in the state shown in FIG. As it rotates, the weight of the driver's cab 1 is transferred to the contact member 5 from the initial start of operation until the center of gravity is on the vertical line of the pivot center.
This will be pushed up while being supported by a.

On the other hand, when the center of gravity passes over the vertical line passing through the pivot center and moves to the left of the vertical line (Fig. 1), the cab 1 moves further counterclockwise due to its own weight. The rod 5 will try to turn itself in the surrounding direction, and after entering this state, the rod 5 will move around the driver's cab 1.
It must be designed to support this movement in a tensile manner.

Hereinafter, the operation of the process from just before the center of gravity of the driver's cab 1 passes through the vertical line will be explained.

When the driver's cab 1 tilts counterclockwise in FIG. 1 around the pivot center, the rods 5
The rod 5 is rotated clockwise relative to the support 3 in a pendulum shape around the intersection 3h in FIG. 3, and the support 3 as shown in FIG.
and the relative position with Rod 5.

During the above transition, the abutment surface 5c changes to the receiving surface 3.
At this time, the back surface 5b uses the female spherical surfaces 3e, 3e as rails and slides on them to enter the female spherical surfaces 3e, 3e. Since the weight of the platform 1 acts in the direction of pulling the rod 5, when this state is entered, the spherical surface 3e fixed to the cab 1 is pressed against the back surface 5b by the gravity. As a result, the pressing force is reduced to the contact member 5a.
and hydraulic actuator 4 via rod 5.
The driver's cab 1 is tilted to a predetermined position while being supported by.

In the above operation, as a practical example, between the rod 5 and the support 3, as the driver's cab 1 is tilted, the rod 5 is tilted relative to the support 3 in the plane shown in FIG. The rod 5 must be able to swing relative to the support 3 to some extent, not only in a clockwise direction relative to the support 3, but also in a direction perpendicular to the plane of the paper in FIG. It consists of a hydraulic actuator 4 and a support 3.
This is because it is necessary to take into account the relative installation error between the driver's cab 1 and the horizontal shaking of the driver's cab 1 when the driver's cab 1 is tilted by the hydraulic actuator 4 or when the vehicle is traveling.

Regarding this problem, in this embodiment, the rocking body 3b is made into a spherical shape, and the spherical surfaces 3e, 3e are configured to pivotally support the rocking body 3b, so that the relative movement of the rod 5 with respect to the support 3 is In addition to being able to perform the above-mentioned rotation horizontally to the plane of the paper, it also allows free rocking other than horizontally, so that when lifting the driver's cab 1 or when the vehicle is running, the support 3 and rod 5
During the relative movement between the two, there will be no unreasonable movement.

In the above action, the end 4a of the hydraulic actuator 4 is pivotally connected to the chassis 2, but conversely, the end 4a is pivotally connected to the driver's cab 1 side, and the support 3
It will be easily understood from the above description that it may be fixedly attached to the chassis 2 side.

As is clear from the above description, in the cab lifting device of the present invention, in the configuration of the normal hydraulic actuator 4, the rod 5 can freely rotate around the axial center of the rod 5. Since the contact member 5a forms a back surface 5b that is symmetrical in the outer circumferential direction of the rod 5, even if the rod 5 rotates around the axis, the shape of the back surface 5b relative to the spherical surface 3e is always the same. It's summery. As a result, the rod 5 does not have to be provided with a complicated device such as a rotation stopper around the center of the axis, and the rear surface 5 can be
b always has spherical surfaces 3e and 3e in the required posture.
It allows you to slide upwards and enter.

Further, the driver's cab lifting device in the present invention has a rear surface 5.
Since b and the spherical surfaces 3e and 3e each have a spherical shape, the mutual contact during the sliding motion is a surface contact, and as a result, it is possible to extremely reduce the surface pressure during the contact. It has the advantage of making it easy to select the material for the contact material 5a and/or the spherical surfaces 3e, 3e, and also reduces the surface pressure of the contact, by using an appropriate bearing material etc. to reduce the frictional force in the contact. It is also possible to reduce it appropriately.

Further, in the driver's cab lifting device according to the present invention, the hemispherical rocking body 3b is sandwiched between the female spherical surfaces 3e, 3e so as to be slidable, and the spherical surface of the back surface 5b of the rod 5 is arranged between the female spherical surfaces 3e, 3e. is used as a rail, and the cab 1 is raised while supporting the weight of the cab 1 by sliding on it. Therefore, only the single female spherical surfaces 3e and 3e are used to support driving, etc. It is possible to escape the relative shaking between the driver's cab 1 and the rod 5 and to prevent lost motion, and to allow the rod 5 to lift the driver's cab 1 while supporting it. As a result, its configuration becomes compact,
It has become possible to reduce the manufacturing cost.

Further, in the driver's cab lifting device according to the present invention, when the swinging body 3b is configured to have the spherical center 3h of the external male spherical surface 3i forming the swinging body 3b, the contact member 5a Even in a lost motion state in which the rocking body 3b is not in contact with the receiving surface 3g, the rocking body 3b can always be held in a state where it is sandwiched between the female spherical surfaces 3e, 3e.

[Brief explanation of drawings]

FIG. 1 shows a driver's cab lifting device according to the present invention,
A side view of the vehicle is shown, FIG. 2 is a sectional view of FIG. 1, FIG. 3 is a sectional view of Rollo in FIG. 2, and FIG. This shows a state in which the abutting member 5a abuts the receiving surface 3g and the rod 5 has completely lifted the driver's cab 1. The symbols used in the examples are as follows.
1: Cab, 2: Chassis, 3: Support, 3a and 3d: Holder, 3b: Rocking body, 3c: Perforation,
3e: female spherical surface, 3f: groove, 3g: receiving surface, 3h:
Center, 3i: male spherical surface, 33j: main body. 4: Hydraulic actuator, 4a: End. 5: Piston rod, 5a: Contact material, 5b: Back surface, 5c: Contact surface.

Claims (1)

[Claims] 1. An end portion 4a of a hydraulic actuator 4 is pivotally connected to either the driver's cab 1 or the chassis 2, and a support 3 is fixed to the other of the chassis or the driver's cab. The support tool includes a pair of holders 3a for forming one female spherical surface.
3d and formed on each of the pair of holders, one spherical surface portion 3e and the other spherical surface portion 3e of the one female spherical surface form a hemispherical rocking body 3.
b are sandwiched so as to be able to swing and slide, the rocking body is formed with a receiving surface 3g, and the rocking body is provided with a hole 3.
A piston rod 5 of the hydraulic actuator is fitted into the hole so as to be able to slide in the axial direction, a contact member 5a is fixed to the piston rod, and a contact member 5a is fixed to the piston rod. an abutting surface 5 that lifts up the driver's cab by abutting against the receiving surface when the piston rod extends upward;
c, and in the abutting member, a male spherical surface is formed on the back surface 5b in the axial direction relative to the abutting surface, making one round in the outer circumferential direction of the piston rod, and the radius of curvature of the male spherical surface is , when the radius of curvature of the female spherical surface of the holder matches, the abutting surface abuts the receiving surface, and the piston rod swings in a pendulum shape about the center of the female spherical surface, A driver's cab lifting device characterized in that the back surface 5b is configured to be able to swing on a female spherical surface 3e. 2. The driver's cab lifting device according to claim 1, wherein the hemispherical shape of the rocking body is a hemispherical shape having a center 3h of the spherical surface of the hemisphere.