Counter weight and work machine

Abstract

To provide a counter weight which can be mounted while stabilizing its posture, and can improve work efficiency in attachment / detachment work of the counter weight, and a work machine including the same.SOLUTION: A counter weight (12) includes a mounted surface (12a), a back face (12b), and a support device (20) capable of mounting the counter weight (12) removed from a machine body (2) while stabilizing the posture of the counter weight (12), wherein the support device (20) has push-in rods (30 and 70) projecting from a lower surface (12c) of the counter weight (12), a gear mechanism (40) interlocked with vertical motions of the push-in rods (30 and 70), and a pair of overhang plates (50 and 52) projecting to each of the side and the back face (12b) of the mounted surface (12a) from the lower part of the counter weight (12) through the gear mechanism (40) by pushing the push-in rods (30 and 70) to the upper side accompanied by mounting of the counter weight (12).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a counterweight that is detachably mounted on a machine body and a work machine equipped with the counterweight. [Background technology]

[0002] A counterweight is detachably attached to the body of a work machine to ensure the machine's balance. When attached to the body, the counterweight has a thin, flat shape extending in the fore-and-aft direction of the machine, and has an attachment surface facing the machine body and a back surface opposite the attachment surface. Because there are weight restrictions when transporting a work machine on a trailer or the like, the counterweight may be detached from the machine body and the machine body and counterweight may be transported separately.

[0003] Patent Document 1 discloses a counterweight with multiple mounts attached to the mounting surface and back surface, with the aim of allowing the counterweight to be placed on a trailer or other loading platform in a stable position without tipping over. The counterweight is formed with a storage compartment for the mounts, and when attaching the counterweight to the machine body, the mounts can be removed from the counterweight and stored in the storage compartment, allowing the mounts to be reused without having to be discarded. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-147963 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned Patent Document 1, in the process of removing the counterweight from the machine body, transporting it, and then attaching it to the machine body, multiple stands must be attached and detached to and from the counterweight each time, which results in a problem of reduced work efficiency in the work of attaching and detaching the counterweight.

[0006] The present invention has been made in view of these problems, and has an object to provide a counterweight that allows the counterweight to be placed with a stable posture and that improves the work efficiency when attaching and detaching the counterweight, and a work machine equipped with the counterweight. [Means for solving the problem]

[0007] In order to achieve the above object, the counterweight of the present invention is a counterweight that is detachably mounted on the body of a work machine, and is equipped with a mounting surface that faces the body when attached to the body, a back surface opposite the mounting surface, and a support device that allows the counterweight to be placed on the body after being removed from the body in a stable position, the support device having a push rod that protrudes from the underside of the counterweight, a gear mechanism that operates in conjunction with the up and down movement of the push rod, and a pair of extension plates that protrude from the bottom of the counterweight on the mounting surface side and the back surface side via the gear mechanism as the push rod is pushed upward as the counterweight is placed on the body. The working machine of the present invention is characterized by including the counterweight described above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a counterweight that allows the counterweight to be placed with a stable posture and that improves the work efficiency when attaching and detaching the counterweight, and a work machine equipped with the counterweight. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of a hydraulic excavator according to an embodiment of the present invention. [Figure 2] FIG. 10 is a front view of a portion of the counterweight as seen from the mounting surface side. [Figure 3] FIG. 2 is a side view of the counterweight. [Figure 4] FIG. 10 is a bottom view of the counterweight. [Figure 5] FIG. 10 is a side view of the counterweight when the support device is activated. [Figure 6] FIG. 10 is a bottom view of the counterweight when the support device is activated. [Figure 7] FIG. 10 is a diagram illustrating the interlocking of the push rod and the pinion. [Figure 8] 10A and 10B are diagrams illustrating the interlocking of the large diameter gear and one of the protruding plates. [Figure 9] 10A and 10B are diagrams illustrating the interlocking of the interlocking gear and the other protruding plate. [Figure 10] FIG. 10 is a side view of a push rod and its surroundings according to a modified example. [Figure 11] 11 is a cross-sectional view of the connection portion of the push rod of FIG. 10 when viewed from the front. [Figure 12] 11 is a side view of the push rod of FIG. 10 when the tip end portion thereof is rotated. DETAILED DESCRIPTION OF THE INVENTION

[0010] A work machine according to one embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows a side view of a hydraulic excavator 1, which is an example of a work machine. The hydraulic excavator 1 has a body 2 made up of a self-propelled crawler-type undercarriage 4 and an upper rotating body 6 rotatably mounted on the undercarriage 4. A work device 8 for performing work such as excavating earth and sand is attached to the front of the upper rotating body 6.

[0011] The working device 8 includes a boom 8a supported on the upper rotating body 6, an arm 8b swingably supported at the tip of the boom 8a, a bucket 8c swingably supported at the tip of the arm 8b, and hydraulic cylinders 8d, 8e, and 8f that drive the boom 8a, arm 8b, and bucket 8c, respectively. The working device 8 swings left and right as the upper rotating body 6 swings, and is configured to be able to move up and down by operation of the hydraulic cylinders 8d, 8e, and 8f.

[0012] The upper rotating body 6 is configured to be able to rotate relative to the lower traveling body 4, and a cab (operator's compartment) 10 where an operator sits is installed above the front side of the upper rotating body 6. A counterweight 12 is detachably installed at the rear of the upper rotating body 6. The counterweight 12 has a thin, flat shape in the fore-and-aft direction X of the machine body, and has an attachment surface (front surface) 12a that faces the upper rotating body 6 when attached to the upper rotating body 6, and a back surface (rear surface) 12b on the opposite side to the attachment surface 12a.

[0013] Figure 2 shows a front view of a portion of the counterweight 12 as seen from the mounting surface 12a side. A support device 20 is built into the counterweight 12, allowing the counterweight 12 to be placed thereon while maintaining a stable posture after being removed from the machine body 2. The support device 20 is located in a storage compartment 14 formed inside the counterweight 12. Note that Figure 2 shows a partial cross section of the periphery of the support device 20, and this also applies to Figures 3 to 6 described below.

[0014] The storage compartment 14 is closed by a cover 16 on the underside 12c of the counterweight 12. In this embodiment, as shown in Figs. 4 and 6 described below, two support devices 20 are arranged on the counterweight 12 in the width direction Y of the machine body, and only one of them is shown in Fig. 2. Also, as shown in Fig. 1, a bolt (fastener) 18 protrudes from the underside 12c of the counterweight 12 for attaching the counterweight 12 to the upper rotating body 6 of the machine body 2. The bolt 18 determines the minimum ground clearance H of the upper rotating body 6 from the ground 22.

[0015] Figure 3 shows a side view of the counterweight 12, and Figure 4 shows a bottom view of the counterweight 12. The support device 20 is made up of a push rod 30, a gear mechanism 40, a pair of extension plates 50, 52, and a support spring 60. The push rod 30 protrudes from the underside of the counterweight 12, and the gear mechanism 40 moves in conjunction with the up and down movement of the push rod 30. Openings 24 are formed in the mounting surface 12a and back surface 12b at the bottom of the counterweight 12, respectively, through which the pair of extension plates 50, 52 can protrude.

[0016] The support spring 60 has a lower end connected to the top of the push rod 30 and an upper end connected to the top wall 14a of the storage chamber 14, thereby supporting the push rod 30. When supporting the push rod 30, the support spring 60 causes the push rod 30 to protrude from the underside of the counterweight 12, and has an elastic force that allows the push rod 30 to be pushed in against the weight of the counterweight 12 as the counterweight 12 is placed. Also, as shown in FIG. 2 , when the counterweight 12 is attached to the upper rotating body 6, a first protrusion length L1 of the push rod 30 protruding from the underside 12c of the counterweight 12 is shorter than a second protrusion length L2 of the bolt 18 protruding from the underside 12c of the counterweight 12.

[0017] Fig. 5 shows a side view of the counterweight 12 when the support device 20 is activated, and Fig. 6 shows a bottom view of the counterweight 12 when the support device 20 is activated. As shown in Fig. 5, when the counterweight 12 is removed from the upper rotating body 6 and placed on the ground 22, the push rod 30 is pushed upward as the counterweight 12 is placed, causing the extension plates 50, 52 to protrude from the openings 24 at the bottom of the counterweight 12 to the mounting surface 12a and back surface 12b, respectively, via the gear mechanism 40. As a result, even if the counterweight 12 is subjected to vibrations on the platform of a trailer or the like and is caused to swing in the direction of the arrows shown in Fig. 5, the counterweight 12 can maintain a stable posture without falling over.

[0018] The operation of the support device 20 will be described in detail below with reference to Figures 7 to 9. Figure 7 is a diagram illustrating the interlocking of the pusher rod 30 and pinion 42. The left part of Figure 7 shows a schematic front view of the mechanism to be described, and the right part of Figure 7 shows a schematic side view of the mechanism to be described. The pusher rod 30 has a first rack 32, shown by a dashed line, extending along its longitudinal direction (vertical direction). The rack is a gear with straight teeth.

[0019] The gear mechanism 40 has a two-stage gear 46 formed integrally with a pinion 42, with which the first rack 32 meshes, and a large-diameter gear 44 that is larger in diameter than the pinion 42. As the counterweight 12 is placed, the push rod 30 is pushed in and moves upward as shown by the arrow (a), causing the pinion 42 to rotate via the first rack 32, and as the pinion 42 rotates, the two-stage gear 46 rotates in the direction of the arrow (b).

[0020] Figure 8 is a diagram illustrating the interlocking of the large-diameter gear 44 and one of the extension plates 50. The left part of Figure 8 schematically shows the front of the mechanism to be explained, and the right part of Figure 8 schematically shows the side of the mechanism to be explained. A second rack 54 is formed on the upper surface 50a of one of the pair of extension plates 50, 52, i.e., the extension plate 50 located on the right side when viewed from the front (front face).

[0021] The large diameter gear 44 of the double gear 46 meshes with the second rack 54. As the double gear 46 shown in Figure 7 rotates, the large diameter gear 44 rotates in the direction of the arrow (c), and as the large diameter gear 44 rotates, one of the extension plates 52 moves in the direction of the arrow via the second rack 54 and protrudes from the opening 24 in the lower part of the counterweight 12 towards the mounting surface 12a (d).

[0022] Figure 9 is a diagram illustrating the interlocking of the interlocking gears and the other overhang plate 52. The upper part of Figure 9 schematically shows the top surface of the mechanism to be described, and the lower part of Figure 9 schematically shows the front surface of the mechanism to be described. A third rack 56 is formed on a first side surface 50b on the left side as viewed from the front (front face) of one of the overhang plates 50. Furthermore, a fourth rack 58 is formed on a second side surface 52a on the right side as viewed from the front (front face) of the other of the pair of overhang plates 50, 52, i.e., the overhang plate 52 located on the left side as viewed from the front (front face).

[0023] The second side surface 52a of the extension plate 52 is positioned opposite the first side surface 50b of the extension plate 50, and an interlocking gear 62 is disposed between the second side surface 52a and the first side surface 50b. The interlocking gear 62 meshes with a third rack 56 and a fourth rack 58 between the pair of extension plates 50, 52. As one extension plate 50 shown in FIG. 8 moves, the interlocking gear 62 rotates in the direction of the arrow via the third rack 56 (e), and as the interlocking gear 62 rotates, the other extension plate 52 moves opposite the one extension plate 50 via the fourth rack 58 and protrudes from the opening 24 in the lower part of the counterweight 12 towards the back surface 12b (f).

[0024] FIG. 10 shows a side view of a pusher rod 70 and its surroundings according to a modified example. Note that in FIG. 10 and FIG. 12 described below, components not used in the description, such as the extension plates 50, 52, are not shown, and components already described are given the same reference numerals and will not be described again. The pusher rod 70 shown in FIG. 10 includes a main body 72, a connecting portion 74, a tip portion 76, and a retaining spring 78. The main body 72 is connected to the lower end of the support spring 60, and the tip portion 76 is rotatably supported at the bottom of the main body 72 via the connecting portion 74. The lower end of the retaining spring 78 is connected to a connecting portion 76a formed on the tip portion 76, and the upper end of the retaining spring 78 is connected to the support spring 60.

[0025] FIG. 11 shows a cross-sectional view of the connection portion 74 when the push rod 70 is viewed from the front. The connection portion 74 is formed by fitting a pin 82 fixed to the lower end of the main body portion 72 into an elongated hole 80 formed at the upper end of the tip portion 76. In the state shown in FIG. 10, the tip portion 76 extends along the longitudinal direction of the main body portion 72 without bending, and protrudes from the underside 12c of the counterweight 12. In this state, the tip portion 76 is pulled upward by the retaining spring 78, which presses the pin 82 against the lower edge of the elongated hole 80. This allows the tip portion 76 to be integrated with the main body portion 72 without rattle, and the support device 20 can be operated by pushing the push rod 70 in as the counterweight 12 is placed.

[0026] 12 is a side view of the push rod 70 when the tip 76 is rotated. The tip 76 is pulled downward against the elastic force of the retaining spring 78 to position the pin 82 on the upper edge of the elongated hole 80, and in this state the tip 76 is rotated in a direction intersecting the main body 72, specifically in a direction approximately perpendicular to the main body 72. The retaining spring 78 holds the tip 76 in a rotated state in the direction intersecting the main body 72, and the rotated tip 76 is positioned above the underside 12c of the counterweight 12. In other words, by rotating the tip 76, the push rod 70 is stored in the storage chamber 14 without protruding from the underside 12c of the counterweight 12.

[0027] As described above, the counterweight 12 of this embodiment is equipped with the support device 20, which has the aforementioned push rod 30, gear mechanism 40, and pair of extension plates 50, 52. When the counterweight 12 is placed, the push rod 30 is pushed upward, which activates the support device 20, and the extension plates 50, 52 protrude from the bottom of the counterweight 12 via the gear mechanism 40 toward the mounting surface 12a and back surface 12b, respectively.

[0028] This allows the counterweight 12 to be placed with its posture stabilized. Furthermore, there are no parts that need to be attached or detached to or from the counterweight 12 each time the counterweight 12 is removed from the upper rotating body 6, transported, and then attached to the upper rotating body 6. Therefore, the counterweight 12 can be placed with its posture stabilized, and the work efficiency in attaching and detaching the counterweight 12 can be improved.

[0029] More specifically, the push rod 30 has a first rack 32, and the gear mechanism 40 has a two-stage gear 46 having the pinion 42 and large-diameter gear 44 described above, a second rack 54 and a third rack 56 of the extension plate 50, a fourth rack 58 of the extension plate 52, and an interlocking gear 62. As described with reference to Figures 7 to 9, the extension plates 50, 52 protrude from the bottom of the counterweight 12 toward the mounting surface 12a and the back surface 12b, respectively, as the support device 20 goes through the operating states (a) to (f).

[0030] The support device 20 also has a support spring 60. When the support spring 60 supports the pusher rod 30, it causes the pusher rod 30 to protrude from the underside 12c of the counterweight 12, and has an elastic force that allows the pusher rod 30 to be pushed in against the weight of the counterweight 12 as the counterweight 12 is placed. This ensures that the pusher rod 30 protrudes from the underside 12c of the counterweight 12 before the counterweight 12 is placed. Therefore, the pusher rod 30 is pushed in as the counterweight 12 is placed, ensuring the operation of the support device 20. Furthermore, when the counterweight 12 is lifted, the pushing of the pusher rod 30 and, therefore, the operation of the support device 20 can be reliably released.

[0031] Furthermore, bolts 18 protrude from the underside 12c of the counterweight 12, and when the counterweight 12 is attached to the upper rotating body 6, a first protrusion length L1 of the push rod 30 protruding from the underside 12c of the counterweight 12 is shorter than a second protrusion length L2 of the bolts 18 protruding from the underside 12c of the counterweight 12. This allows the push rod 30 to protrude from the underside 12c of the counterweight 12 without affecting the minimum ground clearance H of the upper rotating body 6, which is determined by the bolts 18.

[0032] 10 to 12 includes the main body 72, connecting portion 74, tip portion 76, and retaining spring 78 described above, and the rotated tip portion 76 is positioned above the underside 12c of the counterweight 12. This allows the pusher rod 70 to be stored in the storage chamber 14 without protruding from the underside 12c of the counterweight 12. Therefore, when the counterweight 12 is attached to the upper rotating body 6, the pusher rod 70 does not protrude from the underside 12c of the counterweight 12, which eliminates the adverse effects of the pusher rod 70 protruding, such as the aforementioned effect on the minimum ground clearance H of the upper rotating body 6, and also prevents the pusher rod 70 from getting caught on surrounding objects.

[0033] This concludes the description of one embodiment of the present invention, but the present invention is not limited to the above embodiment and various modifications can be made without departing from the spirit of the present invention. For example, the work machine to which the present invention is applied is not limited to the hydraulic excavator 1, and the present invention can be applied to various work machines equipped with a counterweight 12.

[0034] Furthermore, in the above embodiment, two support devices 20 are arranged in the width direction Y of the machine body of the counterweight 12, but the number of support devices 20 is not limited to this, and as long as the counterweight 12 can be placed with a stable posture, one support device 20 may be arranged, or three or more support devices 20 may be arranged. [Explanation of symbols]

[0035] 1 Hydraulic excavator (work machine) 2 aircraft 12 Counterweight 12a Mounting surface 12b Back 12c Bottom 18 Bolts (fasteners) 20 Support device 30 Push rod 32 First Rack 40 Gear mechanism 42 Pinion 44 Large diameter gear 46 Double Gear 50 One of the outriggers 50a top 50b 1st side 52 Other overhanging plate 52a 2nd side 54 2nd Rack 56 3rd Rack 58 4th Rack 60 Support spring 62 Interlocking gears 70 Push Rod 72 Main body 74 Connection 76 Tip 78 Retaining spring L1 1st protrusion length L2 2nd protrusion length

Claims

1. A counterweight that is detachably provided on a body of a work machine, The counterweight has an attachment surface that faces the machine body when attached to the machine body, a back surface opposite to the attachment surface, and a support device that allows the counterweight to be placed on the machine body after being removed from the machine body while stabilizing its posture, The support device includes: A push rod protruding from the underside of the counterweight; a gear mechanism that is interlocked with the up and down movement of the push rod; When the counterweight is placed, the push rod is pushed upward, and a pair of overhanging plates respectively protrude from the lower part of the counterweight toward the mounting surface side and the back surface side via the gear mechanism. A counterweight comprising:

2. the pusher bar has a first rack along its length; The gear mechanism includes: a double gear formed integrally with a pinion that meshes with the first rack and a large-diameter gear that is larger in diameter than the pinion; a second rack formed on an upper surface of one of the pair of protruding plates and meshing with the large diameter gear; a third rack formed on a first side surface of the one of the extension plates; a fourth rack formed on a second side surface of the other of the pair of protruding plates, the second side surface facing the first side surface; an interlocking gear that meshes with the third rack and the fourth rack between the pair of protruding plates; 2. The counterweight of claim 1, comprising:

3. The double gear is configured such that, as the push rod is pushed in and moves upward as the counterweight is placed, the pinion rotates via the first rack, and the large diameter gear rotates in conjunction with the rotation of the pinion, thereby moving one of the protruding plates via the second rack and causing it to protrude from the lower part of the counterweight toward the mounting surface, 3. The counterweight according to claim 2, wherein the interlocking gear rotates via the third rack as the one of the extension plates moves, and moves the other extension plate opposite the one of the extension plates via the fourth rack as the interlocking gear rotates, causing the other extension plate to protrude from a lower portion of the counterweight toward the back surface.

4. The support device includes a support spring that supports the push rod; 4. The counterweight according to claim 3, wherein the support spring causes the pusher rod to protrude from the underside of the counterweight when supporting the pusher rod, and has an elastic force that allows the pusher rod to be pushed in against the weight of the counterweight when the counterweight is placed.

5. a fastener for attaching the counterweight to the aircraft body protrudes from the underside of the counterweight; 5. The counterweight of claim 4, wherein when the support device is not activated, a first protruding length of the pusher rod protruding from the underside of the counterweight is smaller than a second protruding length of the fastener protruding from the underside of the counterweight.

6. The push rod is a main body portion connected to the support spring; a tip portion rotatably supported on a lower portion of the main body portion via a connecting portion; a holding spring having a lower end connected to the tip portion and an upper end connected to the support spring, and holding the tip portion in a rotated state in a direction intersecting the main body portion; and 5. The counterweight according to claim 4, wherein the pivoted tip is positioned above the lower surface of the counterweight.

7. A work machine comprising the counterweight according to any one of claims 1 to 6.

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