JPH0539843Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in a locking mechanism for holding a hydraulic chute provided in a concrete mixer vehicle in a predetermined storage position while the vehicle is running.

(Prior Art) A concrete mixer truck is generally equipped with a chute at the rear of the vehicle body in order to feed the transported fresh concrete from the mixer to a pouring site or a concrete pump. Many of these chute's directions can be changed manually, and the tip can also be rotated up and down to adjust the inclination by expanding and contracting a hydraulic cylinder interposed between the chute and the vehicle body. There is. Also, while the vehicle is running, it is stored in the rear of the vehicle body in a sideways state, and is locked in the stored position by a locking mechanism.

However, in such a lock mechanism, if an attempt is made to rotate the chute by driving the hydraulic cylinder without releasing the lock, the lock mechanism may be damaged. In order to avoid such problems, a locking mechanism as shown in FIG. 5, for example, has been proposed (Japanese Utility Model Publication No. 57-40179).

This is to engage a locking member 20 protruding from the side surface of the chute 1 with a hook 21 provided on the vehicle body 3 side from below, and the hook 21 is engaged with the spring 2
2, the locking member 20 is held in the engaged position, and rotated downward by operating the operating lever 23 to release the locking member 20.
Further, a stopper 24 is provided above the hook 21 to prevent the chute 1 from jumping up and coming off the hook 21 while the vehicle is running. This stopper piece 24 is held in a predetermined position by another spring 25 to prevent the locking member 20 from jumping up, and when the chute 1 is rotated upward from the storage position by the drive of a hydraulic cylinder (not shown), the stopper 24 is held in place by another spring 25. The member 20 is pushed up against the spring 25, and the locking member 20 is disengaged from the hook 21. Therefore, even if the hydraulic cylinder is driven without releasing the hook 21, the lock mechanism will not be damaged.

(Problem to be solved by the invention) By the way, in the case of this lock mechanism, the locking member 2
If the chute 1 enters the engagement position from above, it will interfere with the stopper 24 and will not be able to engage the hook 21. Therefore, when storing the chute 1, the hydraulic cylinder is first contracted to prevent the chute 1 from tilting when stored. , and then rotated to the retracted position. However, depending on the conditions of the location where chute 1 is used,
There are cases where it is necessary to rotate the chute 1 to the retracted position and then retract the hydraulic cylinder to retract the chute 1, and this lock mechanism has a problem in that it cannot cope with such cases. Furthermore, this lock mechanism had a complicated structure because the hook 21 and the stopper 24 were operated separately.

In addition to the above-mentioned lock mechanism, a safety device has also been proposed that prevents the hydraulic actuator from operating unless the lock is released (Japanese Patent Publication No. 58).
−56328). However, in this case, a special electric circuit is required, and the lock must be released before using the chute, making the operation cumbersome.

SUMMARY OF THE INVENTION In order to solve these problems in the locking mechanism of a mixer truck chute, the present invention aims to provide a locking mechanism that has a simple structure and has fewer restrictions on storing and using the chute.

(Means for Solving the Problems) The present invention is a chute for mixer trucks that is attached to the rear of the mixer truck so that it can rotate freely in the horizontal direction, and whose tip can be rotated up and down by the drive of a hydraulic cylinder. A locking member having vertical and horizontal locking portions is provided protrudingly on the vehicle body, and a first hook that engages from the side with the vertical portion of the locking member is rotatably attached to the vehicle body, and is integrated with the first hook. A second hook, which rotates to engage the horizontal portion of the locking member from the side, is erected upward from the first hook, and these hooks are engaged by springs interposed between them and the vehicle body. The hooks are held in the mating position, and oblique guide surfaces for receiving the locking members are formed at the tips of these hooks, and the engaging surfaces of the second hooks are inclined at a predetermined angle in the direction of engagement and disengagement.

(Function) While the diagonal engagement surface formed at a predetermined angle on the second hook prevents the chute from jumping up while traveling, the second hook prevents the chute from upwardly rotating due to the drive of the hydraulic cylinder. The first hook is moved backward against the spring to release the locking member. Also, when storing the chute, if the chute is rotated horizontally from the side, the vertical part of the locking member will move to the first position.
The guide surface of the hook is pressed, and the first hook and the second hook are temporarily retracted to reach the engagement position. When the chute is retracted from above, a similar engagement operation is performed by the horizontal portion of the locking member pressing the guide surface of the second hook and causing it to retreat together with the first hook.

(Example) Embodiments of the present invention are shown in FIGS. 1 to 4.

In FIG. 1, 1 is a chute, and 2 is a locking member protruding from the side surface of the chute 1, including a vertical locking part (vertical part) 2A and a horizontal locking part (horizontal part) 2A.
Equipped with B. As shown in FIG. 4, the chute 1 is rotatably supported via a rotary shaft 4 attached to the rear of a vehicle body 3 of a mixer truck, and its direction can be changed manually within a range of about 180 degrees. Also,
By expanding and contracting a hydraulic cylinder 5 interposed between the rotary shaft 4 and the base end thereof, the distal end thereof is rotated in the vertical direction as shown by the two-dot chain line in the figure. Note that 1A is a foldable extension that is used depending on the conditions at the injection site. When driving, the chute 1 is stored with the tip extension 1A folded upward and the tip facing the side, as shown by the solid line in the figure, and the locking member 2 protruding toward the vehicle body 3 is attached to the locking member 2 shown in FIG. The first hook 6 shown in
The second hook 7 is engaged with the second hook 7 to hold the storage position.

The first hook 6 is a bracket 8 fixed to the vehicle body 3.
is attached to the vertical part 2 of the locking member 2 by a pin 11 so as to be freely rotatable in the horizontal direction, as shown in FIG.
Engage with A from the side. Further, the second hook 7 is erected upward from the first hook 6, rotates together with the first hook 6, and engages with the horizontal portion 2B of the locking member 2 from the side. These hooks 6 and 7 are normally held in the engaged position by a spring 9 interposed between the base end of the first hook 6 and the bracket 8, and an operating lever 10 attached to the first hook 6
As a result of the rotation, the locking member 2 is rotated backward as shown by the broken line in FIGS. 2 and 3, and the locking member 2 is released.

At the tips of these hooks 6 and 7 are oblique guide surfaces 6A for bringing the locking member 2 into the engagement position.
and 7A are formed, respectively. Further, the engaging surface 7B of the second hook 7 is slightly inclined toward the outside. This inclination does not allow the second hook to retreat when the chute 1 jumps up due to the shaking of the vehicle body 3 while the vehicle is running, and the strong thrust force that is applied when the hydraulic cylinder 5 is extended and the chute 1 is rotated upward. The second hook 7 is formed at a small angle θ such that the second hook 7 is rotated backward together with the first hook 6 only when the second hook 7 is rotated backwards.

Next, the effect will be explained.

While driving, the first hook 6 and the second hook 7 engage with the locking member 2 to restrict displacement of the chute 1 due to the shaking of the vehicle body 3, but the engagement surface 7B of the second hook 7 engages with the locking member 2. In order to prevent the vehicle from jumping up, there is no fear that the locking member 2 will disengage while the vehicle is running, and the chute 1 will be reliably held in the retracted position.

When using the chute 1 after the vehicle body 3 has stopped, rotate the operating lever 10 against the spring 9 as shown by the broken line in Figure 2, and the first hook 6 and second hook 7 will rotate and lock. The member 2 is retracted and the chute 1 is released from the locked state. Furthermore, when the hydraulic cylinder 5 is extended and driven without performing this release operation, a strong thrusting force acts on the engagement surface 7B of the second hook 7 via the horizontal portion 2B of the locking member 2, and the second hook 7 rotates backward together with the first hook 6 to release the locking member 2 from the engaged state. Therefore, even if the hydraulic cylinder 5 is driven without forgetting to release the locking member 2, there is no risk of damage to the locking member 2, the hooks 6 and 7, etc.

After using the chute 1, the hydraulic cylinder 5 is contracted and the chute 1 is manually rotated to the storage position. Press
The first hook 6 and the second hook 7 are temporarily rotated backward against the spring 9. When the locking member 2 reaches the engagement position, the first hook 6 and the second hook 7 urged by the spring 9 return to their original positions and engage with the locking member 2, respectively. Also, after rotating the chute 1 to the storage position, the hydraulic cylinder 5
When contracted, the horizontal part 2B of the locking member 2
presses the guide surface 7A at the tip of the second hook 7 to temporarily rotate the first hook 6 and the second hook 7 backward, and after entering the engagement position, the hook 6
and 7. Therefore, the chute 1 may be stored from the side or from above, and in either case, the chute 1 is automatically locked in the stored position without requiring any operation of the operating lever 10.

(Effects of the invention) As described above, the present invention allows the first hook rotatably attached to the vehicle body and the second hook erected thereto to be connected to the vertical and horizontal parts of the locking member protruding from the chute. Since the engagement surface of the second hook is inclined at a predetermined angle in the engagement and disengagement direction, this engagement surface prevents the chute from jumping up while traveling, and
For driving the hydraulic cylinder, the second hook is connected to the first hook.
The locking member is released by moving it backward together with the hook.
In addition, since a diagonal guide surface is formed at the tip of each hook, even when the chute is rotated to the storage position from either the side or the top, the locking member presses the guide surface, allowing the first and second hooks to The two hooks temporarily rotate to receive the locking member and reach the engaged state. In other words, the safety against erroneous operation is high when using the chute, and when the chute is stored, it is automatically locked without being restricted by the rotating direction of the chute, making it easier to lock and release the chute.

Further, since the first and second hooks are rotated together by a single spring and engaged with the locking member, the structure is simple and can be easily implemented.

[Brief explanation of the drawing]

Fig. 1 is a side view of a locking mechanism showing an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a view taken along arrow A-A in Fig. 1, and Fig. 4 is a main part of a mixer truck. FIG. FIG. 5 is a side view of a conventional locking mechanism. DESCRIPTION OF SYMBOLS 1... Chute, 2... Locking member, 2A... Vertical part, 2B... Horizontal part, 3... Vehicle body, 5... Hydraulic cylinder, 6... First hook, 7... Second hook, 6A , 7A...Guide surface, 7B...Engagement surface,
9...Spring.

Claims (1)

[Scope of utility model registration request] A chute 1 for a mixer truck is attached to the rear of the mixer truck so that it can rotate freely in the horizontal direction, and the tip of the chute 1 is rotated up and down by the drive of a hydraulic cylinder. A member 2 is provided protrudingly, and a vertical portion 2 of this locking member 2
A first hook 6 that engages with A from the side is rotatably attached to the vehicle body, and a second hook 6 that rotates together with this first hook 6 and engages with the horizontal portion 2B of the locking member 2 from the side. A hook 7 is erected upward from the first hook 6, and a spring 9 is interposed between the hooks 6, 7 and the vehicle body to bias the hooks 6, 7 in the direction of engagement with the locking member. At the ends of the hooks 6 and 7, the hooks 6 and 7 are rotated against the spring 9 by coming into contact with the locking member 2 during the relative movement of the hooks 6 and 7 in the direction of engagement with the locking member 2. For a mixer truck, the second hook 7 has oblique guide surfaces 6A and 7A for movement, and the engagement surface 7B of the second hook 7 with the locking member 2 is inclined at a predetermined angle in the engagement/disengagement direction. Shoot locking device.