JP4119318B2 - Tipper angle control device for dump truck - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cargo box tilt angle regulating device that regulates the tilting of a cargo box to the left and right in a dump truck, particularly a side dump truck or a three-turn dump truck.
[0002]
[Prior art]
Conventionally, in a three-turn dump truck, when the cargo box is tilted to the left or right, if the cargo box tilts to a predetermined angle, the check valve connected to the hydraulic control circuit is switched to tilt the cargo box. It is known that the extension is restricted, and thereby the tilting of the packing box is restricted to a predetermined angle to prevent the tilting of the packing box (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Registered Utility Model No. 2538859 Publication [0004]
[Problems to be solved by the invention]
However, in the one disclosed in the above-mentioned patent document, when the tilt angle of the packing box is regulated and the cargo box itself tilts more than the regulation angle due to the movement of the load in the packing box, the tilting force is used. There is a problem that an excessive operating force may act on the check valve to damage or break the check valve.
[0005]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a novel dumper cargo box tilt angle regulating device capable of solving the above problems.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is provided with a packing box tilting device including a dump cylinder between a palm frame and a packing box that is tiltably mounted thereon, In the hydraulic circuit connected to the dump cylinder, the dump cylinder is extended by the switching control of the switching valve interposed in the extension side oil passage connecting the oil pump and the oil tank so that the packing box can be tilted. In addition, in the dump truck, a bypass valve is provided in the extension side oil passage, and the hydraulic oil supplied to the dump cylinder is returned to the oil tank by the operation of the bypass valve so as to restrict the tilt of the cargo box over a predetermined angle. ,
The packing box tilting device is provided with a link mechanism that is operated in conjunction with the left and right tilting of the packing box, and a rotating body that is rotated in conjunction with the operation of the link mechanism. The frame is provided with the bypass valve and an actuating member for switching and controlling the actuating member, and the actuating member is actuated following the rotation of the rotating body accompanying the tilting of the cargo box, When tilted to the right by a predetermined angle, the rotating body operates the operating member to switch the bypass valve, stops supplying hydraulic oil to the dump cylinder, and stops the cargo box at the tilted position of the predetermined angle. Further, when the cargo box itself is tilted more than the predetermined angle, the operation of the operating member accompanying the rotation of the rotating body is made ineffective so that excessive operating force is not transmitted to the bypass valve. Yes.
[0007]
According to such a feature, even if the cargo box itself tilted to a predetermined angle tilts more than a predetermined angle due to the movement of the load loaded thereon, it gives excessive operating force to the bypass valve. Therefore, it is possible to prevent the bypass valve from being damaged or broken.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings.
[0009]
FIG. 1 is a side view of a three-wheeled dump truck equipped with the device of the present invention, FIG. 2 is a rear view of the three-wheeled dump truck as viewed in the direction of arrow 2 in FIG. 1, and FIG. 3 is a load along line 3-3 in FIG. 4 is an enlarged plan view of the box tilting device, FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3, FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. FIG. 7 is an enlarged view of the phantom chain line enclosing portion of FIG. 4, FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7, FIG. 9 is a view taken along arrow 9 of FIG. 7 is a sectional view taken along line 10-10 in FIG. 7, FIG. 11 is a sectional view taken along line 11-11 in FIG. 8, and FIG. 12 is a hydraulic circuit diagram of the dump cylinder.
[0010]
Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 12. In this embodiment, the packing box V on the palm frame F can be tilted to the left, right both sides and rearward. In this case, the apparatus of the present invention is applied to a so-called three-turn dump truck. The palm frame F of the three-turn dump truck is configured by placing and fixing a subframe S on a main frame M. The box V is mounted so as to be selectively tiltable to the left, right both sides, and rear.
[0011]
As shown in FIGS. 1 and 2, the front and rear sides of the left and right sides between the packing box V and the subframe S are paired to be hingedly connected to the subframe so as to be detachable. Left and right front hinge mechanisms Hf, Hf and left and right rear hinge mechanisms Hr, Hr are provided, and between the subframe S and the cargo box V, a cargo box tilting device DV having a dump cylinder CD is connected. Of the front hinge mechanisms Hf and Hf and the left and right rear hinge mechanisms Hr and Hr, the left front and rear hinge mechanisms Hf and Hr are all locked, while the right front and rear hinge mechanisms Hf and Hr are both unlocked. If the dump cylinder CD is driven to extend, the cargo box V can be tilted to the left side, and the front and rear hinge mechanisms Hf, Hr on the right side If the dump cylinder CD is extended by operating the left front and rear hinge mechanisms Hf and Hr in the unlocked state and driving the dump cylinder CD to extend, the cargo box can be tilted to the right, and the left and right rear hinge mechanisms. If the dump cylinder CD is driven to extend by operating the left and right front hinge mechanisms Hf and Hf in the unlocked state while operating both the Hr and Hr in the locked state, the cargo box V can be tilted backward.
[0012]
Since both the front hinge mechanism Hf and the rear hinge mechanism Hr are conventionally known, detailed description thereof is omitted.
[0013]
Next, the structure of the packing box tilting device DV will be described mainly with reference to FIGS.
[0014]
The packing box tilting device DV has a pair of lift arms 1 and 1 and a pair of tension links 2 and 2 which are provided to be spaced apart in the left-right direction, and a single-acting hydraulic cylinder connected between them. And a dump cylinder CD.
[0015]
The pair of tension links 2 and 2 are below the lift arms 1 and 1, and one end (front end) of the tension links 2 and 2 is about the longitudinal axis l-l in the front-rear direction and laterally in the left-right direction with respect to the subframe S. It is supported so as to be swingable about the axis tt. That is, the left and right shaft end portions of the first trunnion 3 on the vehicle body side extending in the left-right direction are connected to one ends of the pair of tension links 2, 2 so as to be swingable up and down around the horizontal axis tt. The left and right central portions of the first trunnion 3 are connected to a first cross hinge shaft 4 fixed to the cross member CM of the subframe S and extending in the front-rear direction so as to be swingable left and right around the longitudinal axis l-l. Is done.
[0016]
Further, the other end (rear end) of the pair of lift arms 1 and 1 is swingable up and down around the horizontal axis via the connecting shaft 5 at the other end (rear end) of the pair of tension links 2 and 2. Connected to The lift arms 1, 1 extend forward along the tension links 2, 2, and one end (front end) of the lift arms 1, 1 is about the longitudinal axis l-l in the front-rear direction and the horizontal axis t in the left-right direction with respect to the packing box V -It is supported so as to be swingable around t. That is, one end (front end) of the pair of lift arms 1 and 1 is connected to the left and right shaft ends of the second trunnion shaft 6 on the side of the cargo box extending in the left and right direction so as to be swingable up and down around the horizontal axis tt. The left and right central portions of the second trunnion 6 are fixed to the cross member Vc of the bottom frame of the cargo box V and swing left and right around the longitudinal axis l-l to the second cross hinge shaft 7 extending in the front-rear direction. Connected freely.
[0017]
As shown in FIG. 4, when the dump cylinder CD is in a contracted state, that is, when the packing box V is in a substantially horizontal storage state, the second trunnion 6 is substantially horizontal and close to the first trunnion 3. Is located.
[0018]
The pair of tension links 2, 2 have a substantially straight upper edge and a lower edge protruding downward at the front end, and are formed in a strip shape long in the front-rear direction as viewed from the side, and the first trunnion 3 One end (front end, end portion on the cylinder barrel side) of the dump cylinder CD is connected to the lower portion close to 1 through a support shaft 8 so as to be swingable up and down. In addition, the pair of lift arms 1 and 1 has a lower edge projecting downward and an upper edge projecting upward, and is formed in a rhombus shape that is long in the front and rear directions. The other end (rear end, end on the cylinder rod side) of the dump cylinder CD is connected to the upper apex portion close to 5 by the support shaft 9 so as to be swingable up and down. Therefore, according to the extension operation of the dump cylinder CD, the lift arms 1 and 1 can stand up around the connecting shaft 5 and tilt the cargo box V. At this time, the tension links 2 and 2 are allowed to swing left and right with respect to the subframe S via the first trunnion 3, and the lift arms 1 and 1 are also loaded via the second trunnion 6. As described above, when the packing box V tilts to the left or right side, the packing box tilting device VC can move left and right so as to follow the tilting. Can be swung.
[0019]
In the packing box tilting device DV, the dumping box CD is used to restrict the packing box V from tilting to a predetermined angle or more when the packing box V is tilted to the left or right by a predetermined angle. An angle regulating device VC is attached.
[0020]
Hereinafter, the configuration of the cargo box tilt angle regulating device VC will be described mainly with reference to FIGS. 3 to 11. As shown in FIGS. An angle member 20 is fixed to one end of the trunnion 3, and left and right rotating bodies 30 and 31 described later are connected to the angle member 20 via a link mechanism 21. The link mechanism 21 includes a first link 21a hinged to the angle member 20 and a second link 21b hinged to its free end. The second link 21b is a first link on the subframe S side. The trunnion 3 extends laterally upward toward the center side of the first trunnion 3, and the other ends thereof are the first and second trunnions 3, 6 on the subframe S side and the packing box V side. One end of the operating shaft 22 is rotatably connected on a vertical line passing through the rotation center in the left-right direction. The operating shaft 22 extends substantially horizontally with the upper portion of the cross member CM of the subframe S facing forward, and is rotatably supported by a bearing sleeve 24 fixed to a bracket CMb integrated with the cross member CM. Yes. The center of the swing lever 25 is fixed to the other end of the operating shaft 22 (see FIG. 8).
[0021]
As shown in FIGS. 7 to 9, the swing lever 25 extends in the vertical direction, and upper and lower ends thereof are connected to one ends of upper and lower rods 27 and 28 symmetrically and rotatably. . The upper and lower rods 27 and 28 have turnbuckles, the lengths of which can be adjusted, extend laterally in the direction of approaching each other, and two left and right rotators 30 at their other ends. , 31 are rotatably connected to each other. The left and right rotating bodies 30 and 31 are formed in the same shape and have a fan shape, and their base ends are both fixed to the bracket CMb of the cross member CM and horizontally extended in the front-rear direction. The support shaft 32 is rotatably supported. The left and right rotating bodies 30 and 31 have portions that overlap each other, and are arranged in parallel symmetrically with their phases shifted vertically. As shown in FIGS. 8 and 10, on the outer peripheral surfaces of the left and right rotating bodies 30 and 31, there are first arcuate surfaces 30a and 31a having a radius R1 centered on the axis of the support shaft 32 and slightly more than that. Second arcuate surfaces 30b and 31b having a long second radius R2 are formed adjacent to each other, and the lengths of the first arcuate surfaces 30a and 31a are longer than the lengths of the second arcuate surfaces 30b and 31b. . Further, step portions 30c and 31c made of concave small circular arc surfaces are formed at the boundaries between the first and second arc surfaces 30a and 31a; 30b and 31b.
[0022]
Below the left and right rotating bodies 30, 31, a support shaft 34 parallel to the support shaft 32 is fixed to the cross member CM of the subframe S, and the operating member 33 is freely rotatable on the support shaft 34. Is pivotally supported. The actuating member 33 includes a sleeve 35 that is rotatably fitted to the support shaft 34, a short driven lever 37, a long drive lever 39, and a driven lever 37 that are fixed to the sleeve 35 at an interval in the axial direction. 10 is provided with a follower 38 provided at the free end of FIG. 10 and can be rotated in the direction of arrow a (clockwise) in FIG. 10 by a spring member 36 provided between the sleeve 35 and the support shaft 34. The follower 38 is outside the left and right rotating bodies 30 and 31 and is pressed against the outer peripheral surfaces of the left and right rotating bodies 30 and 31 by the biasing force of the spring member 36. The On the other hand, the drive lever 39 is laterally extended below the left and right rotating bodies 30 and 31 and the tip thereof faces a switching valve of a hydraulic circuit C described later, that is, an operating portion 45 of a bypass valve Vb. 10, when the drive lever 39 rotates in the arrow direction (counterclockwise) in FIG. 10 against the biasing force of the spring member 36, the operation portion 45 is pressed to switch the bypass valve Vb portion. It can be done.
[0023]
FIG. 12 shows a hydraulic circuit C that controls the operation of the dump cylinder CD. In this hydraulic circuit C, a hydraulic pump P driven by a dump truck traveling engine via a power take-off device (PTO) has its suction side connected to the oil tank T and its discharge side on the extension side oil passage 40. Is connected to the high pressure chamber of the single-acting dump cylinder CD via the three-position switching valve Va, and the low pressure chamber of the dump cylinder CD is connected via the return oil passage 41. The oil tank T communicates with the oil tank T. A bypass oil passage 42 is connected between the extension side oil passage 40 and the return oil passage 41, and the bypass valve Vb is connected to the bypass oil passage 42. As described above, the bypass valve Vb is actuated by the drive lever 39. When the valve Vb is in the left position as shown in FIG. 12, the bypass oil passage 42 is closed, When the operating portion 45 is pushed by the drive lever 39 and the bypass valve Vb is switched to the right side, the bypass oil passage 42 is opened, and the high pressure chamber of the dump cylinder CD is communicated with the oil tank T. The cylinder CD becomes free.
[0024]
Next, the operation of this embodiment will be described.
[0025]
Now, as shown in FIG. 12, when the hydraulic pump P is operated and the three-position switching valve Vb is switched to the raised position (UP) in the normal state, that is, the bypass valve Vb is closed, the high-pressure hydraulic oil Is sent to the high-pressure chamber of the dump cylinder CD, and the cargo box V has left and right front and rear hinge mechanisms Hf, Hf; Tilt to one side (left or right) of the palm frame F with Hr as a fulcrum. At this time, the cargo box tilting device DV having the first trunnion 3 on the palm frame F side tilts in the same direction as the cargo box V tilts. When the packing box V is tilted to a predetermined angle set in advance, the first trunnion 3 is also tilted at the same angle in the same direction as the tilting direction of the packing box V.
[0026]
For example, as shown in FIG. 6, when the packing box V tilts to the left, the first trunnion 3 tilts in the same direction. By this tilting, as shown in FIGS. 6 and 8, the swing lever 25 is swung to the left via the link mechanism 21 and the operating shaft 22, whereby the upper rod 27 is pushed to the left and lowered. Since the rod 28 is pulled to the right, the pair of rotating bodies 30 and 31 rotate around the support shaft 32 in the left direction. At this time, when the tilt angle of the packing box V, that is, the rotation angle of the rotating bodies 30 and 31 is within a predetermined angle, the follower 38 of the driven lever 37 is the first arcuate surface 30a of the rotating bodies 30 and 31. , 31a, so that the drive lever 39 is in the position shown by the solid line in FIG. 10 and away from the operating portion 45 of the bypass valve Vb, and the bypass valve Vb remains maintained at the position shown in FIG. The tilting operation of the packing box V is continued.
[0027]
When the tilt angle of the cargo box V reaches a predetermined angle, the follower 38 of the follower lever 37 is stepped on the left rotator 30 by continuing the left rotation of the left rotator 30 interlocked with the link mechanism 21. It gets over the portion 30c and comes into contact with the second arcuate surface 30b. As a result, the driven lever 37 is swung to the left as shown by a chain line in FIG. 10 against the urging force of the spring member 36, and the drive lever 39 is also swung in the same direction. The operation part 45 of the valve Vb is pressed. Thereby, the bypass valve Vb is switched to the right position in FIG. 12, and the high pressure chamber of the dump cylinder CD is communicated with the oil tank T via the bypass oil passage 42, and the extension operation of the dump cylinder CD is stopped. . When the dump cylinder CD contracts to some extent due to the weight of the cargo box V, the follower 38 comes into contact with the first circular arc surface 30a by the clockwise rotation of the rotating body 30, so that the drive lever 39 is connected to the bypass valve. Since it is away from the Vb operating portion 45, the bypass valve Vb is switched to the right position again and the dump cylinder CD is extended. As described above, the packing box V is controlled to stop when it is tilted to a predetermined angle, and the excessive tilting of the packing box V is stopped.
[0028]
By the way, as described above, after the regulation control is performed to the predetermined inclination angle of the packing box V, the packing box V is moved to the predetermined regulation by the movement of the load loaded on the packing box V, in particular, the rapid movement thereof. May tilt more than an angle. At this time, in the conventional device disclosed in the above-mentioned patent document, there is a possibility that the load due to the tilt of the cargo box V directly acts on the check valve (bypass valve), so that the check valve may be damaged or broken. In the embodiment, even if the cargo box V tilts more than the predetermined regulation angle and the rotating body 30 rotates more than the predetermined angle, the follower 38 of the driven lever 37 still remains in the second arcuate surface. Since the state in contact with 30b is continued, even if the cargo box V may be over-tilted, the drive lever 39 will not be over-oscillated, and its operating force will cause the operating portion 45 of the bypass valve Vb to be excessive. The valve Vb can be prevented from being damaged or broken without being pressed.
[0029]
Even when the packing box V is tilted to the right side, the right rotating body 31 performs the control operation of the regulation angle of the packing box V and the damage and prevention of the bypass valve Vb by the same action as described above. Is omitted.
[0030]
As mentioned above, although the Example of this invention was described, this invention is not limited to the Example, A various Example is possible within the scope of the present invention.
[0031]
For example, in the above-described embodiment, the case where the present invention is implemented in a three-wheel dump truck has been described. However, this can also be implemented in a side dump truck. In the above-described embodiment, the dump truck's palm frame is used as a main frame. A dump truck's cargo box tilt angle regulating device is attached to the sub frame with a sub frame, but the shim frame is composed only of the main frame, and the cargo box tilt angle regulating device may be attached to this Of course.
[0032]
【The invention's effect】
As described above, according to the first aspect of the present invention, even if the cargo box itself tilted to a predetermined angle tilts more than a predetermined angle due to the movement of the load loaded thereon, the bypass is bypassed. It is possible to prevent damage and breakage of the bypass valve without giving excessive operating force to the valve.
[Brief description of the drawings]
FIG. 1 is a side view of a three-wheel dump truck equipped with the device of the present invention. FIG. 2 is a rear view of the three-wheel dump truck as shown by an arrow 2 in FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. 3. FIG. 5 is a sectional view taken along line 5-5 of FIG. 4. FIG. 4 is an enlarged view of the phantom chain line enclosing portion of FIG. 4. FIG. 8 is a sectional view taken along line 8-8 in FIG. 7. FIG. 9 is a view taken along arrow 9 in FIG. Cross section [FIG. 11] Cross section along line 11-11 in FIG. 8 [FIG. 12] Hydraulic circuit diagram of dump cylinder [Explanation of symbols]
21... Link mechanism 30... Rotating body (left rotating body)
31 ... Rotating body (right rotating body)
33 ... Actuating member 40 ... Extension side oil passage F ... Shishi frame C ... Hydraulic circuit CD ... Dump cylinder DV ... Packing box tilting device P ... Hydraulic pump T ... Oil tank V ... .... Packing box Va ... Switch valve (3-position switch valve)
Vb ... Bypass valve

Claims (1)

A dump box tilting device (DV) equipped with a dump cylinder (CD) is provided between the palm frame (F) and a load box (V) mounted so as to be tiltable thereon, and the dump cylinder (CD) The dump cylinder (Va) is controlled by switching control of a switching valve (Va) interposed in the extension side oil passage (40) connecting the hydraulic pump (P) and the oil tank (T) in the hydraulic circuit (C) connected to the cylinder (C). CD) is extended so that the packing box (V) can be tilted, and a bypass valve (Vb) is provided in the extension side oil passage (40), and the dump cylinder (Vb) is operated by the operation of the bypass valve (Vb). In the dump truck, the hydraulic oil supplied to the CD) is returned to the oil tank (T) to regulate the tilt of the cargo box (V) beyond a predetermined angle.
The packing box tilting device (DV) is rotated in conjunction with the link mechanism (21) operated in conjunction with the left and right tilting of the packing box (V) and the operation of the link mechanism (21). Rotating bodies (30, 31) are attached, while the palm frame (F) is provided with the bypass valve (Vb) and an operating member (33) for switching and controlling the operating valve. (33) is operated following the rotation of the rotating body (30, 31) accompanying the tilting of the packing box (V), and when the packing box (V) tilts to the left and right by a predetermined angle, the rotation The body (30, 31) operates the operating member (33) to switch the bypass valve, stops supplying hydraulic oil to the dump cylinder (CD), and tilts the packing box (V) by a predetermined angle. And when the packing box (V) itself tilts more than the predetermined angle, The dump truck load is characterized in that the operation of the operating member (33) accompanying the rotation of the rolling elements (30, 31) is ineffective so that an excessive operating force is not transmitted to the bypass valve (Vb). Box tilt angle regulating device.

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