JP6899809B2 - Construction machinery - Google Patents

Description

The present invention relates to a construction machine equipped with a crawler.

For example, construction machines such as hydraulic excavators and bulldozers are provided with a pair of left and right crawlers, and each crawler is configured by wrapping an annular crawler around a drive sprocket, an idler, a truck roller, and a carrier roller. The track is driven by a drive sprocket to run the construction machine, and as it operates, it gradually wears and the tension decreases, so tension adjustment work is carried out on a regular basis.

For example, as described in Patent Document 1, the tension of the track is applied by an adjuster cylinder connected to the idler via a compression spring. An adjuster valve is screwed on one side of the adjuster cylinder, and grease is lubricated and discharged to the adjuster cylinder through this adjuster valve, and the idler is displaced in the front-rear direction accordingly to increase the tension of the track. It will be adjusted.

When the grease is discharged from the adjuster cylinder in order to weaken the tension of the track, the adjuster valve is loosened through the adjusting hole of the cover covering the adjuster cylinder. A discharge groove is formed in the adjuster valve, and when the adjuster valve is loosened, the inside and the outside of the adjuster cylinder communicate with each other through the discharge groove to discharge grease. When the adjuster valve that receives high grease pressure in the adjuster cylinder is unscrewed, the adjuster valve may inadvertently pop out through the adjustment hole of the cover (hereinafter, simply referred to as popping out of the adjuster valve). In some cases). Therefore, it is necessary to perform the loosening operation only before the inside and outside are in communication with each other through the discharge groove and before the screwing is released (still in the middle of screwing).

However, not all workers correctly perform such a grease discharge operation, and some workers carelessly unscrew the adjuster valve. Therefore, for example, a steel plate bracket is fixed in the vicinity of the adjuster cylinder with a bolt, and the tip of the bracket is brought into contact with one side of the adjuster valve at a position before the above-mentioned screwing is released to further loosen the bracket. Measures are being implemented to regulate operations.

Jikkenhei 3-59288 Gazette

However, the conventional measures using the bracket cannot surely prevent the erroneous operation of the operator, and there is room for improvement in terms of cost.
That is, an operator who does not correctly perform the grease discharge operation may not understand the role of the bracket itself. For this reason, for example, if you loosen the bolt that secures the bracket and remove the bracket, or if you forcibly continue the loosening operation to deform the bracket even though it is regulated by the bracket, the original function of the bracket However, as a result, it was not possible to prevent the adjuster valve from popping out.

Further, as is clear from the above description, the bracket is a member permanently installed in the construction machine. For this reason, a pair of brackets is required for each construction machine corresponding to the crawler, which has a problem of affecting the manufacturing cost of the construction machine.

The present invention has been made to solve such a problem, and an object of the present invention is to ensure that the adjuster valve is inadvertently popped out at a low cost when the adjuster valve is loosened and operated in the tension adjustment work of the track. Is to provide construction machinery that can be prevented.

In order to achieve the above object, in the construction machine of the present invention, the adjuster cylinder is arranged in a frame provided with a crawler, and the tension of the crawler's cuffs is adjusted according to the lubrication and discharge of oil and fat to the adjuster cylinder. In a construction machine for adjusting, an adjuster valve that is screwed into the adjuster cylinder and discharges oil and fat in the adjuster cylinder by a loosening operation and a tip that engages with the adjuster valve when arranged in the frame. An adjusting tool having a stepped surface formed on the outer surface, an insertion area formed through a wall surface forming a section of the frame, and an insertion area in which the adjusting tool can be inserted into the frame, and an insertion area, which can be loosened and operated. It is formed adjacent to the insertion region, and in a state where the tip of the adjuster is engaged with the adjuster valve in the frame, the base end of the adjuster is projected to the outside of the frame so that it can be loosened. The adjuster valve is formed on the wall surface so as to surround the rotation operation area of the adjustment hole, and engages with the step surface when the adjuster is loosened. It is characterized by having a barrier surface that prevents the cylinder from jumping out.

According to the construction machine of the present invention, it is possible to reliably prevent inadvertent popping out when the adjuster valve is loosened and operated in the track tension adjusting work at a low cost.

It is a side view which shows the hydraulic excavator of embodiment. It is a detailed view of the part A of FIG. 1 which shows the support structure of an idler. It is a side view corresponding to FIG. 2 which removed the side wall of a side frame. It is a detailed view of part B of FIG. 2 which shows the state which the grease adjuster was inserted into the insertion area of the adjustment hole. It is a VV line cross-sectional view of FIG. 4 which shows the state which the grease adjuster was inserted into the insertion area of the adjustment hole. FIG. 3 is a detailed view of part B of FIG. 2 showing a state in which the grease adjuster is moved from the insertion region of the adjustment hole to the rotation operation region side. FIG. 6 is a cross-sectional view taken along line VII-VII of FIG. 6 showing a state in which the grease adjuster is moved from the insertion region of the adjustment hole to the rotation operation region side. It is sectional drawing corresponding to FIG. 7 which shows the state which the adjuster valve was unscrewed and was prevented from popping out by a collision of a step portion with a barrier surface.

Hereinafter, an embodiment in which the present invention is embodied in a hydraulic excavator will be described.
FIG. 1 is a side view showing the hydraulic excavator of the present embodiment, and first, a schematic configuration of the hydraulic excavator will be described based on the figure. In the following description, the front-back, left-right, and up-down directions are expressed mainly by the operator on the hydraulic excavator.

The lower traveling body 2 of the hydraulic excavator 1 is provided with a pair of left and right crawlers 3, and each crawler 3 includes a drive sprocket 3a located on the rear side, an idler 3b located on the front side, and a pair of carrier rollers 3c located on the upper side. And a large number of track rollers 3d located on the lower side are wound with an annular crawler band 3e. The track 3e is driven via the drive sprocket 3a by a traveling hydraulic motor (not shown), whereby the hydraulic excavator 1 travels.

An upper swivel body 4 is provided on the lower traveling body 2, and the upper swivel body 4 is driven by a swivel hydraulic motor (not shown) to swivel. An articulated work front 5 is provided at the front portion of the upper swing body 4, and the work front 5 is composed of a boom 6, an arm 7, and a bucket 8. The angle of the boom 6 is changed by the boom cylinder 6a, the angle of the arm 7 is changed by the arm cylinder 7a, and the angle of the bucket 8 is changed by the bucket cylinder 8a.

A driver's cab 10 on which an operator rides is provided at the front portion of the upper swing body 4 on the frame 9, and a fuel tank 11, a machine room 12, a counterweight 13 and the like are provided on the rear side of the driver's cab 10 on the frame 9. Has been done. Although not shown, an engine is mounted in the machine room 12, and the above-mentioned traveling or turning hydraulic motors and cylinders 6a to 8a are operated by supplying hydraulic oil from a hydraulic pump driven by the engine.

Although not shown, the track frame of the lower traveling body is formed by connecting side frames 15 (shown in FIGS. 2 and 3 and corresponding to the frame of the present invention) to the left and right sides of the center frame, and the side frames 15 are described above. The driven sprocket 3a, idler 3b, carrier roller 3c and track roller 3d are supported.

FIG. 2 is a detailed view of part A of FIG. 1 showing a support structure of the idler 3b, and FIG. 3 is a side view corresponding to FIG. 2 in which the side wall of the side frame 15 is removed. In the following description, the support structure of the idler 3b provided on the crawler on the left side will be described, but the right side also has the same symmetrical structure.

The support mechanism of the idler 3b is arranged at the front portion in the side frame 15, and is hidden from the outside by the side wall 15a (corresponding to the wall surface forming a section of the present invention) forming the side surface of the side frame 15. The cylinder body 16a of the adjuster cylinder 16 is fixed in the side frame 15, and the retainer 16b is displaced in the front-rear direction according to the amount of grease (corresponding to the oil and fat of the present invention) supplied to the inside thereof. ing.

The idler 3b is rotatably supported by the yoke 17, and a compression spring 18 is interposed between the yoke 17 and the retainer 16b of the adjuster cylinder 16. When the retainer 16b is displaced in the front-rear direction by the adjuster cylinder 16, the idler 3b is also displaced in the front-rear direction together with the compression spring 18 and the yoke 17, whereby the tension of the track 3e is adjusted.
Further, the compression spring 18 exerts an impact absorbing action, and when a crushed stone or the like collides with the crawler 3 while the hydraulic excavator 1 is advancing, the compression spring 18 bends in the compression direction to absorb the impact.

FIG. 4 is a detailed view of part B of FIG. 2 showing the adjuster valve, and FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4 showing the adjuster valve. In addition, FIGS. 4 and 5 show an adjusting hole formed in the side wall 15a of the side frame 15 and a grease adjusting tool (corresponding to the adjusting tool of the present invention) inserted in the insertion region of the adjusting hole.
An adjuster valve 20 is screwed on the outer peripheral surface of the cylinder body 16a of the adjuster cylinder 16 along the axis C1 from the side wall 15a side, and grease is supplied and discharged to the adjuster cylinder 16 via the adjuster valve 20. Cylinder.

The adjuster valve 20 includes a screw portion 20a screwed into a screw hole 16c formed in the cylinder body 16a, a greasing portion 20b protruding from the cylinder body 16a toward the side wall 15a of the side frame 15, and a periphery of the greasing portion 20b. It is composed of a hexagonal nut portion 20c formed in the above. The tip of the screw portion 20a is in close contact with the cylinder body 16a side to form a metal touch portion X, and the metal touch portion X maintains oil tightness between the inside of the cylinder body 16a and the outside (inside the side frame 15). There is. A grease discharge groove 20e extends from the tip end side of the adjuster valve 20 on the outer circumference of the screw portion 20a, one end thereof is connected to the metal touch portion X, and the other end is an annular groove formed on the base end side of the screw portion 20a. It communicates with 20f. Therefore, the grease discharge groove 20e in the normal state is shielded from the cylinder body 16a by the metal touch portion X. 20d is an O-ring.

Then, when grease is supplied to the grease supply portion 20b of the adjuster valve 20 with a grease gun, the grease is guided into the cylinder body 16a through an internal passage (not shown), and the grease is supplied by the built-in check valve. Backflow is prevented.
Further, when the adjuster valve 20 is loosened by the rotation operation with respect to the nut portion 20c (hereinafter, this operation is referred to as a loosening operation), the screw portion 20a gradually protrudes to the outside and the sealing by the metal touch portion X is released. , The sealing by the O-ring is also released. As a result, the inside of the cylinder body 16a and the outside communicate with each other through the grease discharge groove 20e, and the grease in the cylinder body 16a is discharged to the outside through the grease discharge groove 20e.

The tension adjusting work of the track 3e is carried out by, for example, the following procedure.
First, the hydraulic excavator 1 is jacked up to separate the track 3e from the ground surface, and then the height difference L between the lowermost portion of the loose track 3e and the lower surface of the side frame 15 is measured as shown in FIG. .. The height difference L correlates with the tension of the crawler belt 3e, and when the height difference L is larger than the specified value, the tension of the crawler belt 3e is insufficient, so that the adjuster valve 20 is greased with a grease gun. As a result, the amount of grease in the cylinder body 16a of the adjuster cylinder 16 increases, and the tension of the track 3e is strengthened by the forward positional displacement of the idler 3b.

On the contrary, when the height difference L is smaller than the specified value, the tension of the track 3e is excessive, so the adjuster valve 20 is loosened and operated to discharge the grease. As a result, the amount of grease in the cylinder body 16a is reduced, and the tension of the track 3e is weakened by the rearward displacement of the idler 3b. By repeating the above-mentioned grease feeding and discharging, the track 3e is adjusted to the optimum tension.

By the way, as described in [Background Art], if the adjuster valve 20 is unscrewed when the grease is discharged, the adjuster valve 20 will inadvertently pop out due to the grease pressure. In order to prevent such a problem, in the present embodiment, the adjuster valve 20 is loosened and operated by using the grease adjuster 22 provided with the pop-out prevention function, and the configuration thereof will be described below.

FIG. 6 is a detailed view of part B of FIG. 2 showing a state in which the grease adjuster 22 is moved from the insertion region of the adjustment hole to the rotation operation region side, and FIG. 7 is a rotation operation of the grease adjuster 22 from the insertion region of the adjustment hole. FIG. 6 is a cross-sectional view taken along line VII-VII of FIG. 6 showing a state of being moved to the region side.
As shown in FIGS. 4 to 7, the grease adjuster 22 is made of aluminum, steel, or the like and has a cylindrical shape centered on the axis C2 as a whole, and the adjuster valve 20 is attached to the tip (left side of FIG. 5). A socket portion 22a that can be fitted into the nut portion 20c of the above is recessed. Further, a hexagonal nut portion 22b to which a tool such as a socket wrench can be engaged is formed at the base end (right side in FIG. 5) of the grease adjusting tool 22.

A stepped surface 22c is formed on the outer peripheral surface (corresponding to the outer surface of the present invention) of the grease adjusting tool 22 over the entire circumferential direction, and a portion on the tip end side of the grease adjusting tool 22 (hereinafter, hereinafter) with the stepped surface 22c as a boundary. The outer diameter D2 of the large diameter portion 22d) is set to be larger than the outer diameter D3 of the portion on the proximal end side (hereinafter referred to as the small diameter portion 22e). Therefore, the stepped surface 22c has an annular shape facing the base end side of the grease adjusting tool 22.

Further, the grease adjuster 22 is provided with a through hole 22f along the axis C2, one end of which is opened in the socket portion 22a and the other end of which is opened on the nut portion 22b. Therefore, when the socket portion 22a of the grease adjuster 22 is fitted into the nut portion 20c of the adjuster valve 20, the tip of the grease gun is inserted into the through hole 22f to supply grease to the grease portion 20b of the adjuster valve 20. It can be greased.

On the other hand, an adjusting hole 24 is formed in the side wall 15a of the side frame 15 in order to operate the adjuster valve 20 from the outside by using the grease adjusting tool 22.
As a whole, the adjusting hole 24 has a keyhole shape formed by a large-diameter circular insertion region 24a and a small-diameter circular rotation operation region 24b. In the lateral view shown in FIG. 6, the rotation operation region 24b of the adjustment hole 24 is formed so as to coincide with the axis C2 of the adjuster valve 20, and the insertion region 24a is formed adjacent to the front side of the rotation operation region 24b. There is. The position of the insertion region 24a with respect to the rotation operation region 24b is not limited to the front side as long as the same keyhole-shaped adjustment hole 24 is formed, and may be formed on the rear side of the rotation operation region 24b. Alternatively, it may be formed on the upper side or the lower side.

As shown in FIG. 5, the inner diameter D1 of the insertion region 24a is set to be slightly larger than the outer diameter D2 of the large diameter portion 22d of the grease adjuster 22, and the grease adjuster 22 is inserted into the side frame 15 via the insertion region 24a. It can be inserted into. Further, the inner diameter of the rotation operation region 24b is shown in FIG. 7 as the same diameter as the outer diameter D3 of the small diameter portion 22e of the grease adjuster 22, but it is much larger than the outer diameter D3 due to the tolerance setting which is a so-called gap fit. It is set slightly larger.
However, the setting of the inner diameter of the rotation operation region 24b is not limited to this, as long as it is larger than the outer diameter D3 of the small diameter portion 22e of the grease adjuster 22 and smaller than the outer diameter D2 of the large diameter portion 22d. , Can be changed arbitrarily.

When the small diameter portion 22e of the grease adjusting tool 22 is positioned in the rotation operation region 24b of the adjusting hole 24, the socket portion 22a can be fitted into the nut portion 20c of the adjuster valve 20 and the nut portion can be fitted as shown in FIG. 22b projects to the outside of the side frame 15 via the rotation operation region 24b. Since the inner diameter of the rotation operation region 24b is larger than the outer diameter D3 of the small diameter portion 22e as described above, the adjuster valve 20 is loosened by rotating the grease adjuster 22 by engaging the tool with the nut portion 22b. In addition to being possible, the position displacement of the grease adjuster 22 in the axis C2 direction is also allowed.

Then, in the lateral view shown in FIG. 6, the stepped surface 22c of the grease adjuster 22 faces the arcuate region E indicated by hatching formed on the side wall 15a so as to surround the rotation operation region 24b, and this region E The adjuster valve 20 is prevented from popping out due to the collision between the step surface 22c and the step surface 22c, and is hereinafter referred to as a barrier surface E.

The position of the stepped surface 22c in the axis C2 direction of the grease adjusting tool 22 is set as follows.
As shown in FIG. 7, the adjuster valve 20 from the screwed state of the adjuster valve 20 to the cylinder body 16a to the state where the metal touch portion X is released from the sealing by the loosening operation and the grease is discharged. Let the amount of movement be L3. On the other hand, the amount of movement of the adjuster valve 20 until the loosening operation is continued and pop-out occurs due to the unscrew is set to L2 (> L3).

On the other hand, in a state where the socket portion 22a of the grease adjuster 22 is fitted into the nut portion 20c of the adjuster valve 20, the stepped surface 22c is separated from the side wall 15a of the side frame 15 by a distance L1. The adjuster valve 20 described above is set to be larger than the movement amount L2 until the screw is released.

Next, a procedure by an operator when the grease adjusting tool 22 configured as described above is used for the tension adjusting work of the track 3e will be described.
First, after jacking up the hydraulic excavator 1 as described with reference to FIG. 1, the nut portion 22b of the grease adjusting tool 22 is gripped, and as shown in FIGS. insert. The grease adjuster 22 is arranged in the side frame 15, and when the grease adjuster 22 is moved from the insertion region 24a to the rotation operation region 24b side as shown in FIGS. The small diameter portion 22e fits into the rotation operation region 24b. As a result, the stepped surface 22c of the grease adjusting tool 22 faces the barrier surface E of the side wall 15a. Then, the socket portion 22a is fitted into the nut portion 20c of the adjuster valve 20 while pushing the nut portion 22b into the adjusting hole 24, relying on the feel of the hand.

In this state, if it is determined that the tension of the track 3e is insufficient based on the measured height difference L, the tip of the grease gun is inserted into the through hole 22f of the grease adjuster 22 to lubricate the adjuster valve 20 with grease. To do.
If it is determined that the tension of the track 3e is excessive based on the height difference L, the tool is engaged with the nut portion 22b of the grease adjusting tool 22 to loosen the track. The adjuster valve 20 moves toward the side wall 15a in response to the loosening operation, and the distance L1 between the stepped surface c of the grease adjusting tool 22 and the barrier surface E of the side wall 15a shown in FIG. 7 gradually decreases accordingly. Then, when the screwing of the adjuster valve 20 is released by the movement amount L3, grease starts to be discharged from the adjuster valve 20, and when the desired discharge amount is reached, the grease adjuster 22 is rotated in the reverse direction to return the adjuster valve 20. Return to the screwed state.

Since a socket wrench or the like is used for the normal loosening operation of the adjuster valve 20 and grease is discharged into the side frame 15, it is difficult for the operator to visually grasp the discharged amount. When the grease adjusting tool 22 of the present embodiment is used, the grease discharged from the adjuster valve 20 is guided to the outside of the side frame 15 through the through hole 22f. Therefore, the operator can easily visually grasp the amount of grease discharged, and can stop the grease discharge at a desired amount. As a result, repeated lubrication and discharge of grease for adjusting the tension of the track 3e to the optimum tension can be kept to the minimum necessary, and the adjustment work can be carried out efficiently.

Further, by forming the through hole 22f, not only the grease can be discharged but also the grease can be supplied while the grease adjusting tool 22 is attached to the adjuster valve 20. Grease lubrication and discharge are repeated for optimum tension adjustment of the track 3e, but since it is not necessary to attach and detach the grease adjuster 22 each time, this factor also greatly contributes to efficient adjustment work.

On the other hand, if the operator correctly understands the grease discharge operation as described above, the loosening operation is stopped when the start of grease discharge from the through hole 22f is confirmed (corresponding to the movement amount L3). However, in the case of an operator who does not understand correctly, the loosening operation is continued, and when the movement amount L2 shown in FIG. 7 is reached, the adjuster valve 20 pops out due to the unscrew.

Even at this point, since the distance L1 between the stepped surface 22c of the grease adjusting tool 22 and the side wall 15a of the side frame 15 remains to some extent, the grease adjusting tool 22 has a side wall along the axis C2 together with the adjuster valve 20 that has received the grease pressure. It moves to the 15a side, and as shown in FIG. 8, the stepped surface 22c collides with the side wall 15a, specifically, the barrier surface E on the peripheral edge of the rotation operation region 24b shown in FIG. Since the side wall 15a of the side frame 15 has a sufficient thickness, the grease adjusting tool 22 is received with a margin, and as a result, the situation where the adjuster valve 20 together with the grease adjusting tool 22 protrudes to the outside through the adjusting hole 24 of the side wall 15a is prevented. Therefore, even if an operator who does not correctly understand the grease discharge operation adjusts the tension of the track 3e, the adjuster valve 20 should be loosened to prevent inadvertent popping out. Can be done.

On the other hand, the grease adjusting tool 22 of the present embodiment includes not only the hydraulic excavator 1 but also a crawler as long as various conditions such as the shape of the adjusting hole 24 and the distance between the adjuster valve 20 and the side wall 15a are common. Since it is used for construction machines, it can be reused between each construction machine. The only necessary measure on the side of the hydraulic excavator 1 is to form the adjusting holes 24 on the side walls 15a of the left and right side frames 15. As a result, it can be carried out at a very low cost as compared with the conventional technique in which a bracket needs to be permanently installed for each construction machine.

Further, a keyhole-shaped shape is adopted as the adjusting hole 24 to be formed in the side wall 15a. The side wall 15a is a member that requires extremely high strength because it forms the side surface of the side frame 15 that supports the crawler 3. Therefore, the opening formed in the side wall 15a is required to be kept in the minimum necessary area regardless of the purpose, and this requirement is the same for the adjusting hole 24.

As is clear from the above description, the insertion region 24a of the adjusting hole 24 has a minimum shape (slightly larger than the outer diameter D2 of the large diameter portion 22d) into which the grease adjusting tool 22 can be inserted from the outside, and is rotated. The region 24b has a minimum shape (larger than the outer diameter D3 of the small diameter portion 22e and the outer diameter of the large diameter portion 22d) capable of projecting the nut portion 22b of the grease adjuster 22 to the outside and preventing the region 24b from protruding to the outside. Smaller than D2). As a result, since the adjusting hole 24 itself is also limited to the minimum necessary opening area, it is possible to achieve the above-mentioned effects while maintaining the side wall 15a and the side frame 15 with high rigidity.

However, the adjusting hole 24 of the present invention is not limited to the shape of a keyhole, and can be arbitrarily changed as long as it has a shape consisting of an insertion area 24a into which the grease adjusting tool 22 can be inserted and a rotation operation area 24b capable of preventing popping out. Can be done.

Although the description of the embodiment is completed above, the aspect of the present invention is not limited to this embodiment. For example, in the above embodiment, the hydraulic excavator 1 is embodied, but the construction machine provided with a crawler is not limited to this, and may be applied to, for example, a bulldozer.

Further, in the above embodiment, the adjuster valve 20 has both the functions of grease lubrication and discharge, but the present invention is not limited to this. For example, the adjuster valve 20 has a function of only grease discharge, and grease is not included. It may be carried out by the nipple or the like.

Further, in the above embodiment, the distance L1 between the stepped surface 22c of the grease adjuster 22 and the side wall 15a of the side frame 15 is set to be larger than the movement amount L2 until the adjuster valve 20 is unscrewed. Not limited. For example, the distance L1 may be set as a value larger than the movement amount L3 until the grease is discharged from the adjuster valve 20 by the loosening operation and smaller than the movement amount L2 until the screw is released.

In this case, if the loosening operation is continued even though the grease has begun to be discharged, the stepped surface 22c of the grease adjusting tool 22 comes into contact with the barrier surface E of the side wall 15a before the screwing is released. The side wall 15a having high strength receives the stepped surface 22c without being deformed like the bracket of the prior art. Therefore, further loosening operations are restricted and the adjuster valve 20 is prevented from being unscrewed, so that the same effect as that of the above embodiment can be obtained.

1 Hydraulic excavator (construction machinery)
3 crawler 3e track 15 side frame (frame)
15a side wall (wall surface)
16 Adjuster Cylinder 20 Adjuster Valve 22 Grease Adjuster (Adjuster)
22c Step surface 22d Large diameter part 22e Small diameter part 22f Through hole 24 Adjustment hole 24a Insertion area 24b Rotation operation area E Barrier surface

Claims (5)

In a construction machine in which an adjuster cylinder is arranged in a frame provided with a crawler and the tension of the track of the crawler is adjusted according to the lubrication and discharge of oil and fat to the adjuster cylinder.
An adjuster valve that is screwed into the adjuster cylinder and discharges oil and fat in the adjuster cylinder by loosening operation.
When the tip is engaged with the adjuster valve when it is arranged in the frame, it can be loosened and operated, and an adjuster having a stepped surface formed on the outer surface.
An insertion region is formed so as to penetrate a wall surface forming a section of the frame, and the adjuster can be inserted into the frame, and the tip of the adjuster is formed in the frame adjacent to the insertion region. An adjustment hole formed by a rotation operation area that allows the base end of the adjuster to protrude to the outside of the frame so that it can be loosened while engaged with the adjuster valve.
A barrier surface is formed on the wall surface so as to surround the rotation operation region of the adjustment hole, and engages with the step surface to prevent the adjuster valve from popping out to the outside when the adjuster is loosened. A construction machine characterized by being equipped. The adjuster has a cylindrical shape composed of a large diameter portion on the tip side and a small diameter portion on the proximal end side, and the stepped surface forming an annular shape facing the proximal end side between the large diameter portion and the small diameter portion. Is formed,
The adjusting hole is a circular insertion region larger than the outer diameter of the large diameter portion of the adjusting tool, and a circle larger than the outer diameter of the small diameter portion of the adjusting tool and smaller than the outer diameter of the large diameter portion. The construction machine according to claim 1, wherein the construction machine has a keyhole shape formed by the rotation operation region of the shape. The barrier surface is characterized in that when the adjuster valve is unscrewed, it collides with a stepped surface of the adjuster that moves toward the wall surface side together with the adjuster valve that has been subjected to grease pressure. The construction machine according to 1. The construction according to claim 1, wherein the barrier surface comes into contact with a stepped surface of the adjuster before the adjuster valve is unscrewed to prevent the adjuster valve from being unscrewed. machine. The construction machine according to claim 1, wherein a through hole is provided in the adjuster from the tip end to the base end.

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