JPH0147354B2 - - 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, the piston rod (hereinafter simply referred to as rod) 5 in FIG.
Rod 5 in the figure shows the position after the driver's cab 5 has started to be lifted.

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 FIG. 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.

As shown in FIGS. 2 and 3, the structure of the support 3 is such that 3 m of bearing material is fixed to the support 3.
The rotor 3a is inserted into the holes 3k and 3j formed in the support 3, respectively.
A concave spherical bearing surface 3c is fitted to allow sliding rotation around the central axis of the rotor 3a and is cut into the rotor 3a.
A member 3b forming a convex spherical bearing surface 3i is swingably supported, and a rod 5 is fitted into a hole 3d formed in the member 3b to enable sliding movement in the axial direction of the hole. However, on both sides of the space 3f in which the rod 5 can swing and rotate around the axial center of the rotor 3a, and on the upper side of the rotor 3a in the direction of gravity in the state shown in FIG. Provide rails 3e, 3e forming a convex spherical surface centered at the intersection 3h of the axis and the central axis of the perforation 3d,
The rails 3e, 3e are fixed to the support 3. Note that 3p is a support member for preventing the member 3b from coming off, and 3q is a C ring.

The rod 5 has a shoulder 5c (Fig. 3) that selectively abuts the side end 3g of the member 3b, and a disc-shaped collar 5a is screwed onto the tip of the rod 5. The back surface 5b on the side forms a concave spherical surface having the same curvature as the above-mentioned convex spherical surface formed on the rails 3e, 3e.

To explain its function in the above configuration, in the state shown in Fig. 2, that is, in the state in which the rod 5 is retracted the shortest possible time, the driver's cab has 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 vibrates.
This enables a lost motion in which the rod 5 can freely vibrate vertically in the portion of the perforation 3d, and the riding comfort resulting from this vibration is independent of the structure of the other shock absorbers (not shown). With this device, the vibrations can be damped and made comfortable.

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 operated and the rod 5 is extended, the shoulder 5c of the rod 5 is
eventually comes into contact with the side end 3g as shown in FIG. Lift the platform 1 as shown in FIG.

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 supported by the shoulders 5c and pushed up from the initial start of operation until the center of gravity is on the vertical line of the pivot center.

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 rod 5 tilts clockwise relative to the support 3 around the intersection 3h in FIG. Rotate in the direction. In this case, as described above, the shoulder 5 is already kept in contact with the side edge 3g, and in this state, the center of gravity of the driver's cab 1 is aligned with the vertical line passing through the pivot center as described above. From a position slightly before passing, the concave spherical surface of the back surface 5b slides onto the rails 3e, 3e forming a part of the convex spherical surface, while the collar 5a moves clockwise in FIG. 3, centering on the intersection 3h. As it rotates further and the rod 5 extends further from this state, as mentioned above,
Since the weight of the driver's cab acts in a direction that pulls the rod 5, when this state is entered, the rail 3e fixed to the driver's cab 1 is pressed against the back surface 5b by the gravity. As a result, the pressing force is supported by the hydraulic actuator 4 via the collar 5a and the rod 5, and the driver's cab 1 is tilted to a predetermined position.

In the above action, as a practical matter, between the rod 5 and the support 3, as the driver's cab 1 is tilted, the rod 5 moves relative to the support 3 within the plane of FIG. The rod 5 must be able to swing relative to the support 3 to some extent not only in the relative clockwise direction, but also in the 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, member 3
b has a spherical shape, and the bearing surface 3c pivotally supports the member 3b, so that the support 3 of the rod 5
The relative movement is such that it is possible to perform the above-mentioned rotation horizontal to the plane of the paper in FIG.
When lifting the driver's cab 1 or when the vehicle is running, the relative movement between the support 3 and the rod 5 is such that no unreasonable movement occurs. .

In addition, in the above action, the rod 5 is at the intersection 3h.
A configuration that can rotate counterclockwise in the plane of FIG. 1 with the spherical member 3 as the center is
If b is directly supported by the support 3, not only the rotation of the rod 5 in the counterclockwise direction, but also the
Although it is possible to perform a rocking movement against escape such as the above-mentioned horizontal vibration, the reason why this embodiment has a structure in which a spherical member is particularly pivotally supported on the rotor 3a is as follows.

That is, the surfaces of the bearing surface 3c and the bearing surface 3i are
There are cases where the bearing requires an oil seal for lubricating material or a dust seal as necessary, but in this case, the bearing surfaces 3c and 3i
This is because, since the seal is spherical, if the swing angle at the bearing surface is large, the seal may be easily damaged.

As a result, in order to deal with the above-mentioned problems, in this embodiment, on the one hand, between the member 3b and the rotor 3a, any small swing (about 5 ),
On the other hand, the large rocking rotation caused by lifting the driver's cab 1 is caused by the rod 5 coming into contact with the wall portion of the perforation 3n formed in the rotor 3a. Rotor 3a
These are integrally configured to be able to rotate around the central axes of the perforations 3k and 3j.

Note that the configuration that allows relative rocking between the rod 5 and the support 3 does not necessarily require a configuration in which the rotor 3a pivotally supports the spherical member 3b, as in the above-mentioned embodiments. It may be configured as a universal joint in which two pins are rotatably orthogonal to each other, and in short, it is sufficient to provide a configuration that allows swinging of about 5 degrees between the support 3 and the hydraulic actuator 4. The basic condition of the present invention is that the rod 5 rotates and oscillates with respect to the support 3 about at least one axis perpendicular to the rod 5.
It is necessary that the back surface 5b at a is configured to be able to fit into the rails 3e, 3e. As a result, if the value of the oscillation that is allowed to be about 5 degrees is very small, the rotor 3a is configured to allow sliding in the axial direction of the perforation 3k or 3j. The rotor 3a and the member 3b may be configured as an integral rotating member to allow the vibration to escape.

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 collar 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 rail 3e always remains the same. There is. 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 is always in the required position, rails 3e,
It is possible to slide up and into 3e.

Further, the driver's cab lifting device in the present invention has a rear surface 5.
b and the rails 3e, 3e mutually have spherical shapes, the mutual contact during the sliding motion is a surface contact, and as a result, it is possible to extremely reduce the surface pressure at the contact, and the brim 5a and/or the rails 3e, 3e, and in order to reduce the surface pressure of the contact, an appropriate bearing material or the like is used to moderate the frictional force in the contact. It is also possible to lower the amount.

In addition, in the driver's cab lifting device according to the present invention, when the rotor 3a is configured to pivotally support the spherical member 3b, in order to smoothly escape the horizontal shaking of the driver's cab 1, the support 3, This eliminates the risk of damaging the rod 5 or the hydraulic actuator 4 or reducing their durability.

[Brief explanation of drawings]

FIG. 1 shows a schematic side view of a driver's cab lifting device according to an embodiment of the present invention installed in an automobile, and FIG. 2 shows a support device 3 in FIG. 1.
FIG. 3 shows a cross-sectional view taken along the Rollo line in FIG. 2. The symbols used in the examples are as follows.
1: Cab, 2: Chassis, 3: Support, 3a:
Rotor, 3b: member, 3c and 3i: bearing surface,
3d, 3k and 3j: perforation, 3e: rail, 3
f: Space, 3g: Side edge, 3h: Intersection, 3m:
Bearing material, 3n: perforation. 4: Hydraulic actuator,
4a: End. 5: Piston rod, 5a: Brim,
5b: Back, 5c: Shoulder.

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 device includes rotating members 3a and 3b that are rotatable about at least one shaft vertically erected to the side of the driver's cab.
a borehole 3d perpendicular to the one axis is bored in the rotating member, and a piston rod of the hydraulic actuator is fitted into the borehole to enable sliding movement in the axial direction of the borehole. The piston rod between the rotating member and the hydraulic actuator is fixed with a shoulder 5c that abuts against the rotating member and lifts up the driver's cab, and the piston rod has a shoulder 5c that is fixed to , a collar 5a is fixed to the opposite side of the shoulder in the axial direction of the piston rod, and is located on the opposite side of the shoulder of the rotary member and in a part of an arc shaped around the one axis of the rotary member. , rails 3e, 3e forming a convex spherical surface centered on the intersection 3h of the one axis and the central axis of the perforation are provided on the supports located on both sides of the axis of the piston rod. A concave spherical surface portion having the same radius of curvature as the spherical surface is formed in the outer circumferential direction of the piston rod on the back surface 5b on the shoulder side of the brim, so that when the driver's cab is lifted, the back surface is A driver's cab lifting device, characterized in that it is configured to slide on the rail. 2 The rotating member has holes 3j,
The rotor 3a is fitted to the rotor 3k so that it can rotate and slide.
and a spherical member 3b pivotably supported on the rotor, and a perforation 3d formed in the rotating member is formed in the member 3b. A driver's cab lifting device according to claim 1.