JPH0669089U - Automatic track tension adjustment device for tracked vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] The track tension can be adjusted automatically without human intervention. [Structure] The idler 1 is supported by an idler yoke 4 and is attached to a cylinder 5 directly connected to the rear of the idler yoke 4,
A piston 6 that is fitted in and out by a grease is fitted inside, front and rear spring retainers 7 and 8 and a recoil spring 9 are provided behind the piston 6, and the idler 1 is moved by the movement of the cylinder 5 to adjust the track tension. Grease pump 1 driven by expansion and contraction of spring 9
0 is placed on the sling press 7 so as to operate integrally, and the grease pump 10 is provided with the first plunger 15, the second plunger 17 and the like in the case 14 to provide the grease in the grease tank 11. Is stored in the grease chamber 25 through the second plunger 17, and when an external force acts on the idler 1 in a direction to contract the recoil spring 9, the spring retainer 7 is moved to supply the grease into the second plunger 17. Then, when the external force is released, the grease in the grease chamber 25 is fed into the cylinder 5 and automatically adjusted in the direction in which the crawler belt is stretched.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a track adjuster for a tracked vehicle, and more particularly to an automatic track adjuster for a tracked vehicle that automates track adjustment.

[0002]

[Prior art]

 Conventionally, the underbody structure of a tracked vehicle generally has a structure as shown in FIG. 4, for example, in the case of a bulldozer. That is, the crawler belt 43 is provided around the sprocket 41 and the idler 42, and when the sprocket 41 rotates, the crawler belt 43 rotates to drive the vehicle. Here, 44 is a vehicle body, 45 is an earthwork plate, and 46 is a truck frame in which a recoil spring case is housed. In the above structure, the distance between the sprocket 41 and the idler 42 is always kept constant, and if it is too loose, the running of the vehicle becomes unstable. That is, if there is excessive slack, the crawler belt 43 will come off and the vehicle will be unable to run. Therefore, in order to keep the tension of the crawler belt 43 constant, the idler 42 is movable to some extent in the horizontal direction so that the idler 42 is always tensioned outward with a constant load.

However, in the conventional crawler belt tension adjusting device, for example, as shown in the side view of FIG. 5, an idler yoke 47 attached to a track frame 46 supports an idler 42 via a shaft (not shown). The front end of the piston rod 48 is attached to the tip of the idler yoke 47. The piston rod 48 is fitted inside a cylinder 49 for adjustment except for the front end. An outer peripheral end of the cylinder 49 is formed with a flange 50, and is attached so that one end of a recoil spring 51 fitted on the cylinder 49 comes into contact with the flange 50. The other end of the recoil spring 51 is in contact with the bottom 53a of the case 53 of the recoil spring 51 slidably fitted to the outer periphery of the grease guide 52 formed integrally with the other end of the cylinder 49. Is installed in. Then, the inlay portion 53b of the bottom 53a is fitted into the hole 54a of the support plate 54 fixed to the track frame 46, and the nut 55 for screwing with the screw provided at the end of the grease guide 52 is screwed. The set length of the recoil spring 51 is set by tightening. A grease fitting 56 is attached to an end surface of the grease guide 52. The track tension is adjusted by using the grease gun 57 on the grease fitting 56 to inject the grease from the grease fitting 56 into the cylinder 49 through the hole of the grease guide 52 and push out the idler 42. Was going by.

Further, as a grease pump conventionally used for crawler belt tensioning, there is one having a structure as shown in FIG. 6, for example. A crank 59, which is rotatably connected to the periphery of the disk 58, and one end of a plunger 61, which slides in the grease cylinder chamber 60, are connected by a pin 62, and the other end of the plunger 61 has a grease. In the cylinder chamber 60, there is a greasing passage 63 extending in a straight line, and this greasing passage 63 is connected to a feed port 65 via a check valve 64. The upper part of the grease cylinder chamber 60 communicates with the grease tank 66, and the grease in the grease tank 66 is introduced into the grease cylinder chamber 60. When the disk 58 is rotated by a motor (not shown), the plunger 61 slides in the cylinder chamber 60 to feed the grease into the greasing passage 63, open the check valve 64, and open the feed port 65 to a desired position. Is to be greased.

[0005]

[Problems to be solved by the device]

 However, the above-mentioned adjustment of the crawler track must be made to the predetermined size unless the dimension check of the track frame 46 and the crawler track 43 and the press-fitting of the grease (manually using the grease pump) are repeated several times. Therefore, adjustment takes time. In addition, when using a grease gun, grease easily adheres to the undercarriage device, and once attached to the undercarriage, dirt and sand tend to adhere to it, so it does not become muddy and falls off. -I do not want to do the adjustment work easily, and if I do not adjust it, the looseness will be severe and it will be a problem that the track will come off.

In the above case, however, since the stroke L of the plunger 61 has a dead stroke 1, it is difficult to say that the stroke L is effective, and in order to secure a sufficient discharge amount. Stroke L must be made longer. However, when the stroke L is lengthened to increase the discharge amount Q (indicated by the length), the air in the grease in the grease cylinder chamber 60 collects into a large bubble and the plunger 61 slides. However, the problem occurs that only air can be sent. Also, since the crank 59 is used, when no force acts on the center line of the plunger 61, the bending moment acts on the plunger 61, and the plunger 61 damages the sliding surface of the cylinder chamber 60, which causes The plunger 61 may be damaged.

Therefore, there is an application (of Japanese Utility Model Application No. 4-67210) in which the applicant solves the above-mentioned problems and automatically adjusts the crawler belt tension. In this structure, as shown in FIG. 7, a crawler belt 72 is wound between an idler 71 and a sprocket (not shown), a shaft 73 of the idler 71 is supported by an idler yoke 74, and is directly connected to the rear of the idler yoke 74. The piston 75 that moves in and out by grease is installed in the cylinder 75, and front and rear spring retainers 77, 78 and recoil spring 79 are provided behind it, respectively. By moving the cylinder 75, the idler 71 is moved to tension the crawler belt. For adjustment, a grease pump 80 driven by expansion and contraction of a recoil spring 79 is integrated with a front spring retainer 77, and a grease pump 80 has a grease passage 81 and a grease passage leading to a cylinder 75. 82 and 83 are provided respectively. The detailed structure of the grease pump 80 is, as shown in FIG. 8, a first plunger 85 which is slid by expansion and contraction of a recoil spring 79, a set spring 86 which prevents excessive pressure feed of the grease, and a slidable second plunger 87. The return spring 88 and the return spring 88 are installed in that order in the case 84, and check valves 89 and 90 are provided in the passage 82 of the case 84 to the grease reservoir 81 and the passage 83 to the cylinder 75, respectively. When the recoil spring 79 is expanded or contracted by this, the grease pump 80 is driven to operate so that the grease in the grease reservoir 81 is supplied to the cylinder 75 from the passage 83, so that the manpower is increased. It allows automatic adjustment without adding.

However, in the case of the prior application described in the preceding paragraph, even if the second plunger 87 slides, sufficient compression cannot be obtained because of the return spring 88, and the second plunger 87 slides as in the preceding paragraph. When it was moved, the grease was not pumped, but only the air was pumped, and the automatic adjustment did not work well.

Further, in the case of a hydraulic power shovel for automatically adjusting the track tension, there is a track shock absorber for a bulldozer which is equipped with an automatic greasing pump. Since the suspension device has a greasing pump, it is not possible to greas the swivel joint of the upper revolving structure, and there is a concern that the track will be too tight due to the lack of a pressure detection function. It was

In view of this, the present invention provides an automatic crawler belt tension adjusting device for a tracked vehicle by improving the above-mentioned drawbacks so that the crawler belt tension adjustment can be surely automatically performed without any manual operation. The purpose of the invention is to eliminate the drawbacks of the prior art.

[0011]

[Means for Solving the Problems]

 According to claim 1 of the present invention as a means for solving the above-mentioned problems of the prior art, a crawler belt is wound between an idler and a sprocket, and a shaft of the idler is supported by an idler yoke. A piston that goes in and out by grease is fitted in a cylinder that is directly connected, and front and rear spring retainers and recoil springs are provided behind it, and the idler is moved by the movement of the cylinder to adjust the track tension. In a track tension adjusting device for a tracked vehicle, a grease pump driven by expansion and contraction of the recoil spring is integrally provided on the front spring retainer, and the grease pump reaches the grease tank and the cylinder. A grease passage is provided in each case, and the grease pump expands and contracts the recoil spring in the case. A large-diameter first plunger that slides more, a pipe-shaped second plunger that is fitted behind a small-diameter plunger hole and has a grease hole that communicates from the outer diameter to the inner diameter, and the second plunger A boss fixed at one end, a grease feed valve that can be brought into contact with and separated from the other end, a return spring for the boss, and a boss and a grease feed valve are integrally connected in the second plunger. According to a second aspect of the present invention, the boss head of the second plunger that presses the rear surface of the first plunger by the return spring is a spherical surface.

[0012]

[Action]

 According to the above-mentioned structure, the grease pump or the greasing pump is driven by the expansion and contraction of the recoil spring so as to be supplied to the cylinder from the passage of the grease tank. It can be automatically adjusted without any need for inspection and adjustment.

[0013]

【Example】

 FIG. 1 is a side view (cross section) showing an embodiment of an automatic crawler belt tension adjusting device for tracked vehicles according to claims 1 and 2 of the present invention, and FIG. 2 is a cross sectional view showing details of the grease pump of FIG. 3 is an operation diagram of FIG.

Hereinafter, claims 1 and 2 of the present invention will be described with reference to an embodiment shown in FIGS. 1 to 3. According to claim 1 of the present invention, a crawler belt 2 is wound around an idler 1 and a sprocket (not shown), a shaft 3 of the idler 1 is supported by an idler yoke 4, and the cylinder is directly connected to the rear of the idler yoke 4. 5, a piston 6 which moves in and out by grease is fitted in the inside, and front and rear spring retainers 7 and 8 and a recoil spring 9 are provided behind the piston 6, respectively, and the idler 1 is moved by the movement of the cylinder 5 to tension the crawler belt. In the track tension adjusting device for a tracked vehicle, the grease pump 10 driven by the expansion and contraction of the recoil spring 9 is integrally provided on the spring retainer 7 at the front part, and the grease pump 10 is adjusted. 10 is provided with a grease tank 11 and grease passages 12 and 13 leading to the cylinder 5, respectively, and the grease pump 10 is provided with a case 14. Is a pipe-shaped first plunger 15 having a large diameter that slides due to the expansion and contraction of the recoil spring 9, and a grease hole 17a that is fitted behind a plunger hole 16 having a small diameter and that communicates from the outer diameter to the inner diameter. The second plunger 17, the boss 18 fixed to one end of the second plunger 17, the grease feed valve 19 that can be brought into contact with and separated from the other end, the return spring 20 of the boss 18, the boss 18 and the grease. And a connecting spring 21 that integrates the feed valve 19 with the second plunger 17 in one body. In claim 2, the rear surface of the first plunger 15 is pressed by the return spring 20 in claim 1. The boss head 18a of the second plunger 17 has a spherical surface.

In FIG. 1, the cylinder 5 is formed with a flange portion 5a at the front end, and the other side of the grease passage 13 connected to one end of the grease pump 10 is connected to the flange portion 5a. Grease is introduced into the front part of the inside. The rear surface of the piston 6 that comes into contact with the grease in the cylinder 5 is provided so that the projection 7a at the center of the spring retainer 7 at the front comes into contact. The protrusion 7a extends rearward in a rod shape to form a stopper 7b having a slightly larger end, and one side of the recoil spring 9 is attached to this large diameter. The other side of the recoil spring 9 comes into contact with a large-diameter rear spring retainer 8 to apply tension to the crawler belt by a load attached between the spring retainers 7 and 8. Further, the spring retainer 8 is fixed to the vehicle body side, and when the spring retainer 7 moves to the front side, the stopper 7b is brought into contact with the inner face of the spring retainer 7 so as to penetrate the protrusion 7a of the spring retainer 7. It is formed to stop the movement. The spring retainer 7 is prevented from moving to the front side by a stopper 22 fixed to the vehicle body side at the front portion. The grease pump 10 is integrally fixed to the stopper 7b of the spring retainer 7.

As shown in FIG. 2, the structure of the grease pump 10 is such that the first plunger 15 installed in the case 14 is formed with a protrusion 15a whose front end surface contacts the rear surface of the spring retainer 8. , So as to protrude from the outer surface of the case 14. A second plunger 17 is slidably fitted in a plunger hole 16 provided concentrically at the back of the hole into which the first plunger 15 provided in the case 14 is fitted. The second plunger 17 has a pipe-like shape and is provided with a plurality of grease holes 17a communicating with the inside and outside at an intermediate portion of its length. A boss 18 is fixed to one end of the second plunger 17. It is provided so as to contact the rear surface. Further, the detachable grease delivery valve 16 comes into contact with the other end to form a seal surface between the two. Then, in order to be able to contact again when it is separated from the second plunger 17, it is connected to the boss 18 by a connecting spring 21. One end of the return spring 20 is attached to the flange portion of the boss 18, and the other end is attached to a side surface inside the case 14. The grease tank 11 is provided in a radial direction in which the grease passage 12 provided in the case 14 is desired, and an internal cartridge grease 23 is pressurized by a spring 24 so as to pass through the passage 12 through the passage 12. 2 It is designed to be pushed out to the plunger 17 side. The difference between the length of the plunger hole 16 and the length of the second plunger 17 is the stroke of the second plunger 17, and this difference forms the grease cylinder chamber 25. 2 and 3, reference numeral 26 is a check valve.

Next, the operation will be described. First, when a foreign object is caught in a sprocket (not shown) or a pitch jump occurs while the vehicle is running, the idler 1 moves to the right in FIG. 1 against the extension force of the recoil spring 9 and accordingly. The cylinder 5, the piston 6, the spring retainer 7, and the grease pump 10 which are integrated with the idler 1 move to the right. At this time, the repulsive force of the return spring 20 causes the first plunger 15 to move to the left, so that the protruding portion 15a is maximally protruding from the case 14 and the passage 12 has a negative pressure. The grease pressurized by the spring 24 reaches the second plunger 17 through the passage 12 and is sent into the inside of the second plunger 17 through the grease hole 17a. When the grease fills the inside of the second plunger 17, the pressure increases, and the grease feed valve 19 is opened to flow into the grease cylinder chamber 25. Next, when foreign substances on the sprocket are removed and the pitch jump ends and the normal condition is restored, the idler 1 also returns the piston 5, the spring retainer 7, and the grease pump 10 to the left. The return spring 20 is compressed as in 3, and the second plunger 17 is moved to the right. This compresses the grease in the cylinder chamber 25. When the pressure becomes higher than the pressure in the cylinder 5, the check valve 26 is opened and the check valve 26 is supplied to the inside of the cylinder 5 through the passage 13, so that the amount of grease in the cylinder 5 increases and the idler 1 increases. The track 2 to the cylinder 5 moves to the left, so the tension of the crawler belt 2 is strengthened. Then, after the crawler belt 2 has reached the proper state, the grease pressure in the cylinder 5 rises, and the grease feed to the cylinder 5 is stopped. The boss 18 of the second plunger 17 is in spherical contact with the rear plane of the first plunger 15, and the center line of the first plunger 15 and the center line of the second plunger 17 do not move in line with each other. However, the external force transmitted from the first plunger 15 always acts on the center line of the second plunger 17. The first plunger 15 does not tilt and lock by sliding inside the case 14 and transmitting an external force to the boss 18. Therefore, the bending moment does not work on the second plunger 17, there is no fear of breakage as in the conventional case, a sufficient discharge amount can be obtained even with a short stroke, and air does not accumulate in the grease cylinder chamber 25. Since the external force always acts on the center line of the second plunger 17, there is no need to worry about damage to the second plunger 17.

[0018]

[Effect of device]

 As described above, according to the present invention, the crawler belt is wound around the idler and the sprocket, the shaft of the idler 1 is supported by the idler yoke, and the cylinder directly connected to the rear of the idler yoke is connected by the grease. Adjusting the track tension of a tracked vehicle in which a piston that goes in and out is fitted inside, and front and rear spring retainers and recoil springs are provided behind it, and the idler is moved by the movement of the cylinder to adjust the track tension. According to a first aspect of the present invention, a grease pump driven by expansion and contraction of the recoil spring is provided integrally with the front spring retainer, and the grease pump has a grease passage leading to the grease tank and the cylinder. And the grease pump slides in the case by expansion and contraction of the recoil spring. A first plunger, and a pipe-shaped second plunger which is fitted in a plunger hole having a small diameter behind the first plunger and has a grease hole communicating from the outer diameter to the inner diameter, and fixed to one end of the second plunger. A boss, a grease feed valve which can be brought into contact with and separated from the other end, a return spring for the boss, and a connecting spring which integrates the boss and the grease feed valve in the plunger. In claim 2, since the boss head of the plunger that presses the rear surface of the first plunger by the return spring is a spherical surface, the tension of the crawler belt is automatically adjusted. Problems such as mixing and over-tensioning of the track are eliminated by the present invention.

[Brief description of drawings]

FIG. 1 is an explanatory side view showing an embodiment of an automatic crawler belt tension adjusting device for a tracked vehicle according to claim 1 of the present invention.

2 is an explanatory view with a cross section of an embodiment showing the structure of the grease pump of FIG. 1. FIG.

FIG. 3 is an explanatory diagram showing an operating state of FIG.

FIG. 4 is an explanatory view showing the appearance of a known bulldozer.

FIG. 5 is an explanatory side view of an example of a crawler belt tension adjusting device for a conventional tracked vehicle.

FIG. 6 is an explanatory view showing an example of a defect in the structure of the grease pump portion of the conventional crawler belt tension adjusting device.

FIG. 7 is an explanatory side view showing an embodiment of an automatic crawler belt tension adjusting device of the prior application.

FIG. 8 is an explanatory view in cross section showing the structure of the grease pump of FIG. 7.

[Explanation of symbols]

1 idler 16 plunger hole 2 crawler belt 17 second plunger 3 shaft 17a grease hole 4 idler yoke 18 boss 5 cylinder 19 grease feed valve 6 piston 20 return spring 7 front spring retainer 21 connecting spring 8 rear spring retainer 9 Recoil spring 10 Grease pump 11 Grease tank 12, 13 Grease passage 14 Case 15 First plunger

Claims (2)

[Scope of utility model registration request] 1. A crawler belt is wound between an idler and a sprocket, a shaft of the idler is supported by an idler yoke, and a piston which moves in and out by a grease is inserted into a cylinder directly connected to the rear of the idler yoke. In the track tension adjusting device for a tracked vehicle, which is fitted with a front and rear spring retainer and a recoil spring, respectively, and which adjusts the track tension by moving the idler by the movement of the cylinder. A grease pump driven by expansion and contraction is provided integrally with the spring retainer at the front part, the grease pump is provided with a grease passage leading to the grease tank and the cylinder, and the grease pump is provided with a casing. The large-diameter first plunger that slides in the space due to the expansion and contraction of the recoil spring, and It is fitted in a small diameter plunger hole,
And a pipe-shaped second plunger having a grease hole communicating from the outer diameter to the inner diameter, a boss fixed to one end of the second plunger, and a grease feed valve capable of coming into contact with and separating from the other end.
An automatic crawler belt tension adjusting device for a track-tracked vehicle, comprising: a return spring for the boss and a connecting spring that integrates the boss and the grease feed valve in the second plunger. 2. The automatic track tension adjusting device for a tracked vehicle according to claim 1, wherein the boss head of the second plunger that presses the rear surface of the first plunger with a return spring is a spherical surface. .