JP5101550B2 - Cylinder rod protection structure - Google Patents

Description

  The present invention relates to a cylinder rod protection structure including a protection cover that is provided in a work machine such as a hydraulic excavator having a hydraulic cylinder that drives a work device and protects a cylinder rod included in the hydraulic cylinder.

  There exists a thing shown by patent document 1 as this kind of prior art. This conventional cylinder rod protection structure is provided in a hydraulic excavator, and is arranged on the upper side of the cylinder rod, and a flat plate guide member made of spring steel for protecting the cylinder rod, that is, a protective cover is attached to the cylinder rod. It is attached to the tip and configured to move together with the cylinder rod. With this configuration, the cylinder rod can be protected from an obstacle by the protective cover, and the durability of the hydraulic cylinder including the cylinder rod can be improved.

  Although not described in Patent Document 1, as is well known, the temperature of the hydraulic oil guided to the hydraulic cylinder described above is high, and therefore, a conduit for returning the hydraulic oil discharged from the hydraulic cylinder to the hydraulic oil tank Is provided with an oil cooler for cooling the hydraulic oil returned to the hydraulic oil tank.

Japanese Patent No. 4038197

  The prior art disclosed in Patent Document 1 described above considers protection from obstructions of the cylinder rod of the hydraulic cylinder, but the temperature of the hydraulic oil discharged from the hydraulic cylinder and guided to the oil cooler is transferred to the oil cooler. No consideration has been given to reducing it before the inflow of water. For this reason, conventionally, there is a concern that the durability of the oil cooler deteriorates due to the heat load of the high-temperature hydraulic oil that flows in.

  The present invention has been made from the actual situation in the above-described prior art, and an object of the present invention is to provide a cylinder rod protection structure capable of cooling the hydraulic oil guided to the oil cooler before flowing into the oil cooler. is there.

In order to achieve this object, a cylinder rod protection structure according to the present invention includes a hydraulic cylinder that drives a working device and an oil cooler that cools hydraulic oil that is discharged from the hydraulic cylinder and guided to a hydraulic oil tank. The cylinder rod protection structure is provided with a protective cover for protecting the cylinder rod included in the hydraulic cylinder attached to the cylinder rod so that the cylinder rod can be moved integrally with the cylinder rod. Provided between the cylinder tube of the hydraulic cylinder and the protective cover is a radiating fin comprising a plurality of plate-like members extending along the extending direction of the protective cover , and the cylinder rod of the radiating fin Of the end located on the side closer to the cylinder and the end located far from the cylinder rod To respectively, is characterized in that the formation of the curved portion or the tapered portion.

  In the present invention configured as described above, the cylinder tube is cooled by the heat radiating fins provided between the cylinder tube of the hydraulic cylinder and the protective cover, and thereby, the high-temperature hydraulic oil guided to the hydraulic cylinder including the cylinder tube. Can be cooled. That is, the working oil guided to the oil cooler can be cooled before flowing into the oil cooler. That is, the hydraulic oil can be guided to the oil cooler with the temperature of the hydraulic oil lowered.

  Moreover, the cylinder rod protection structure according to the present invention is characterized in that, in the above invention, the radiating fin is provided on an outer peripheral surface of the cylinder tube. In the present invention configured as described above, the radiation fins can be provided relatively easily.

Furthermore, cylinder rod protection structure according to the present invention, in the above invention, the heat radiation fin is characterized in that also serves as a guide member for guiding the protective cover that moves on Symbol cylinder rod and integrally. The present invention configured as described above can smoothly move the protective cover by following the movement of the cylinder rod through the heat dissipating fins also serving as the guide member.

  The cylinder rod protection structure according to the present invention is characterized in that, in the above invention, a friction reducing member is provided between the radiation fin and the protective cover. In the present invention configured as described above, the protective cover can be moved more smoothly via the friction reducing member.

  Moreover, the cylinder rod protection structure according to the present invention is characterized in that, in the above invention, the protective cover has a circular arc shape surrounding the cylinder rod in a cross-sectional shape in a direction orthogonal to the extending direction. In the present invention configured as described above, since the protective cover is formed in a shape along the outer peripheral surface of the cylinder rod, it is possible to ensure an excellent protection function against the cylinder rod from an obstacle.

The present invention provides a plurality of plate-like bodies extending along the extending direction of a protective cover between a cylinder tube of a hydraulic cylinder in which the cylinder rod is accommodated so as to be able to advance and retract and a protective cover for protecting the cylinder rod. Since the heat dissipating fins are provided , and the end portions located on the side closer to the cylinder rod of the heat dissipating fins and the end portions located on the side far from the cylinder rod are formed with curved surfaces or tapered portions, The hydraulic oil guided to the hydraulic cylinder by the fins can be cooled, and the hydraulic oil guided to the oil cooler can be cooled before flowing into the oil cooler. That is, the hydraulic oil can be guided to the oil cooler in a state where the temperature of the hydraulic oil is lowered as compared with the conventional one. As a result, the heat load applied to the oil cooler by the high temperature hydraulic oil can be reduced as compared with the conventional case, and the life of the oil cooler can be extended.

  In addition, when it is sufficient to obtain the same level of durability as the conventional one, the capacity of the oil cooler can be reduced, and downsizing of the oil cooler can be realized. Thereby, the manufacturing cost concerning the oil cooler can be reduced as compared with the conventional one, and the degree of freedom for the arrangement design of the oil cooler can be increased as compared with the conventional one.

1 is a side view showing a hydraulic excavator cited as an example of a work machine provided with a first embodiment of a cylinder rod protection structure according to the present invention. It is a top view which shows the principal part structure of the turning body with which the hydraulic shovel shown in FIG. 1 is equipped. FIG. 2 is a hydraulic circuit diagram showing a hydraulic drive device provided in the hydraulic excavator shown in FIG. 1. It is A sectional expanded view of FIG. 1 is an exploded perspective view showing a first embodiment of a cylinder rod protection structure according to the present invention. It is a figure which shows the arm cylinder part which comprises the principal part of 1st Embodiment shown in FIG. 5, (a) A figure is a side view, (b) A figure is a front view. It is a figure which shows the arm cylinder part which comprises the principal part of 2nd Embodiment of this invention, (a) A figure is a side view, (b) A figure is a front view .

  Embodiments of a cylinder rod protection structure according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing a hydraulic excavator cited as an example of a working machine provided with the first embodiment of the cylinder rod protection structure according to the present invention, and FIG. 2 is a main part of a swing body provided in the hydraulic excavator shown in FIG. FIG. 3 is a hydraulic circuit diagram showing a hydraulic drive device provided in the hydraulic excavator shown in FIG.

  The hydraulic excavator shown in FIG. 1 includes a traveling body 1, a revolving body 2 disposed on the traveling body 1, and a work device 3 attached to the revolving body 2 and performing various operations such as excavation work. . The work device 3 includes a boom 4 provided on the swing body 2 so as to be pivotable in the vertical direction, an arm 5 provided on the tip of the boom 4 so as to be pivotable in the vertical direction, and a vertical direction at the tip of the arm 5. And a bucket 6 that is rotatably provided. Further, a hydraulic cylinder that drives the work device 3, that is, a boom cylinder 7 that drives the boom 4, an arm cylinder 8 that drives the arm 5, and a bucket cylinder 9 that drives the bucket 6 are provided. The revolving body 2 is provided with a cab 10 in which an operating device for operating the hydraulic cylinder described above is disposed.

  As shown in FIGS. 2 and 3, the above-described boom cylinder 7, arm cylinder 8, bucket cylinder 9, turning motor 17 for turning the turning body 2, and traveling for running the traveling body 1 are run on the turning body 2. The hydraulic pump 16 that supplies pressure oil to various hydraulic actuators such as the right motor 18a and the traveling left motor 18b, the engine 12 that drives the hydraulic pump 16, and the pressure oil that is supplied from the hydraulic pump 16 to the various hydraulic actuators And a control valve 11 for controlling the flow. Furthermore, a fuel tank 13, a hydraulic oil tank 14, and an oil cooler 15 are provided on the revolving structure 2. As shown in FIG. 3, the oil cooler 15 is provided in a conduit 19 that guides hydraulic oil discharged from the hydraulic cylinder to the hydraulic oil tank 14 via the control valve 11, and hydraulic oil that is guided to the hydraulic oil tank 14. That is, the return oil is cooled.

  4 is an enlarged cross-sectional view of FIG. 1A, FIG. 5 is an exploded perspective view showing the first embodiment of the cylinder rod protection structure according to the present invention, and FIG. 6 is a main part of the first embodiment shown in FIG. It is a figure which shows an arm cylinder part, (a) A figure is a side view, (b) A figure is a front view.

  The cylinder rod protection structure according to the first embodiment provided in the hydraulic excavator described above is attached to a hydraulic cylinder, for example, an arm cylinder 8. As shown in FIG. 5 and the like, the arm cylinder 8 includes a cylinder rod 8b and a cylinder tube 8a in which the cylinder rod 8b is accommodated so as to be able to advance and retract. In the cylinder rod protection structure according to the first embodiment, the radiation fin 20 is provided between the cylinder tube 8a of the arm cylinder 8 and the protective cover 22 that protects the cylinder rod 8b.

For example, as shown in FIGS. 4 and 6B, the heat dissipating fins 20 are integrally provided on the outer peripheral surface of the cylinder tube 8a. Three are provided so as to protrude. These radiation fin 20 is made of a plurality of plate-like body extending in the along Migihitsuji the extending direction of the protective cover 22, also serves as a guide member for guiding the protective cover 22 that moves integrally with the cylinder rod 8b ing. As shown in FIG. 6, a curved surface portion 20a is formed on each of the end portion located on the side closer to the cylinder rod 8b of the radiating fin 20 and the end portion located on the side far from the cylinder rod 8b.

  As shown in FIGS. 4 and 5, friction reducing members 21 are provided at the upper end portions of the heat radiation fins 20 so as to cover these upper end portions. The friction reducing member 21 is made of, for example, a self-lubricating synthetic resin. As shown in FIG. 5, the arm cylinder 8 is connected to the bracket 4 a provided on the boom 4 at the end 8 a 1 of the cylinder tube 8 a and connected to the bracket 5 a provided on the arm 5 at the tip 8 b 1 of the cylinder rod 8 b. It has come to be.

  As shown in FIG. 4 and the like, the protective cover 22 has a cross-sectional shape in a direction orthogonal to the extending direction thereof, which is an arc shape surrounding the cylinder rod 8b, for example, a semicircular shape whose lower side is opened for heat dissipation. Each of the lower ends of the protective cover 22 is provided with a hook portion 22b which can be slidably contacted with each of the friction reducing members 21 attached to the heat radiating fins 21 protruding in the left-right direction of the outer peripheral surface of the cylinder tube 8a. It is formed.

  As shown in FIG. 5, a bolt hole 22a is formed at one end of the protective cover 22, and a female screw portion 8b2 is formed at the tip 8b1 of the cylinder rod 8b. The bolt 27 is inserted into the bolt hole 22a of the protective cover 22 through the washer plate 25 and the washer spring 26, and is screwed into the female threaded portion 8b2 of the tip 8b1 of the cylinder rod 8b. Is attached to the tip 8b1. Thereby, the protective cover 22 moves integrally with the cylinder rod 8b.

  As described above, the arm cylinder 8 having the protective cover 22 attached to the cylinder rod 8b has, for example, an extension of the cylinder rod 8b according to the hydraulic oil supplied to the bottom chamber in the cylinder tube 8a, and the arm 5 shown in FIG. The cylinder rod 8b contracts in response to the hydraulic oil supplied to the rod chamber in the cylinder tube 8a, and the arm 5 rotates upward, thereby performing a desired operation, for example, a bucket. Excavation work etc. by 6 are carried out. As described above, the hydraulic oil discharged from the arm cylinder 8 through the control valve 11 is cooled by the oil cooler 15 and returned to the hydraulic oil tank 14.

  While the cylinder rod 8b advances and retracts from the cylinder tube 8a, the protective cover 22 moves integrally with the cylinder rod 8b as described above. That is, the protective cover 22 is guided by each of the heat radiating fins 20 via the friction reducing members 21 provided on the heat radiating fins 20, and slides so as to follow the cylinder rod 8b, thereby protecting the cylinder rod 8b from obstacles. To do.

  According to 1st Embodiment comprised in this way, the cylinder tube 8a is cooled by the radiation fin 20 provided in the outer peripheral surface of the cylinder tube 8a of the arm cylinder 8. FIG. As a result, the high-temperature hydraulic oil guided to the arm cylinder 8 including the cylinder tube 8a can be cooled. Thereby, the hydraulic oil guided to the oil cooler 15 can be cooled before flowing into the oil cooler 15. That is, the hydraulic oil can be guided to the oil cooler 15 with the temperature of the hydraulic oil lowered. Thereby, the thermal load given to the oil cooler 15 by the high temperature hydraulic oil can be reduced, and the life extension of the oil cooler 15 can be realized.

  In a situation where it is not necessary to consider so much about durability, the capacity of the oil cooler 15 can be made smaller than before, and the size of the oil cooler 15 can be reduced. Thereby, while being able to reduce the manufacturing cost which concerns on the oil cooler 15, the freedom degree with respect to the arrangement design of the oil cooler 15 can be enlarged more. This is effective when the hydraulic excavator is a mini excavator and is easily restricted by the installation area of the oil cooler 15 due to the arrangement relationship with other devices.

  Further, in the first embodiment, since the radiating fins 20 are provided on the outer peripheral surface of the cylinder tube 8a of the arm cylinder 8, the radiating fins 20 can be provided relatively easily, and the practicality is high.

  Moreover, since the radiation fin 20 also serves as a guide member for guiding the protective cover 20, the protective cover 22 can be smoothly moved by following the movement of the cylinder rod 8b via the radiation fin 20, and the structure is stable. Can be realized. In addition, since the curved surface portions 20 a are formed at both ends of the radiating fin 20, the work of fitting the protective cover 22 into each of the radiating fins 20 can be easily performed.

  In addition, since the friction reducing member 21 is provided at each of the upper end portions of the radiating fins 20, when the protective cover 22 is guided by the radiating fins 20, the protective cover 22 is attached via the friction reducing members 21 as described above. It can be moved smoothly and contributes to the realization of a stable structure.

  Further, since the cross-sectional shape of the protective cover 22 in the direction orthogonal to the extending direction is an arc shape surrounding the cylinder rod 8b, the protective cover 22 has a shape along the outer peripheral surface of the cylinder rod 8b, and the cylinder from the obstacle An excellent protection function for the rod 8b can be ensured, and a highly reliable structure can be realized.

  As illustrated in FIG. 1, the boom cylinder 7 is also provided with a cylinder rod protection structure equivalent to that of the first embodiment including the protection cover 23. The bucket cylinder 9 is also provided with a cylinder rod protection structure equivalent to that of the first embodiment including the protective cover 24. Thus, even in the cylinder rod protection structure provided in the boom cylinder 7 and the bucket cylinder 9, it is possible to obtain the same effect as the cylinder rod protection structure according to the first embodiment described above.

  7A and 7B are views showing an arm cylinder portion constituting a main part of the second embodiment of the present invention. FIG. 7A is a side view, FIG. 7B is a front view, and FIG. 8 is a third embodiment of the present invention. FIG. 9A is a side view, FIG. 9B is a front view, and FIG. 9 is a view showing an arm cylinder part constituting the main part of the fourth embodiment of the present invention. In the figure, (a) is a side view, and (b) is a front view.

  In the second embodiment shown in FIG. 7, the heat dissipating fins 30 that also serve as guide members provided in the upper direction and the left-right direction of the outer peripheral surface of the cylinder tube 8 a of the arm cylinder 8 are formed separately. Of these radiating fins 30, the end of the radiating fin 30 located on the side closest to the cylinder rod 8 b and the end of the radiating fin 30 located on the side farthest from the cylinder rod 8 b and the cylinder rod 8 b located farthest from the cylinder rod 8 b. A curved surface portion 30a is formed at each of the separated end portions. A friction reducing member similar to the friction reducing member 21 in the first embodiment is provided at each upper end portion of the radiation fin 30. Other configurations including the protective cover 22 (not shown) are the same as those in the first embodiment.

Cylinder rod protection structure according to a second implementation form shown in FIG. 7 also, the radiating fin 30 thus cylinder tube 8a is cooled, it is possible to cool the hydraulic oil of high temperature is led to the arm cylinder 8, oil cooler 15 The hydraulic oil guided to the coolant can be cooled before flowing into the oil cooler 15, and the same effect as the cylinder rod protection structure according to the first embodiment can be obtained.

In each of the above embodiments, each of the heat radiating fins 20 and 30 is provided on the outer peripheral surface of the cylinder tube 8a of the arm cylinder 8. However, the heat radiating fins are not formed on the inner surface of the protective cover 22 or the like. It is also possible to provide a configuration in which no heat radiating fin is provided on the outer peripheral surface of the cylinder tube 8a. Also in this configuration, the cylinder tube 8a can be cooled by the radiating fins provided on the inner surface of the protective cover 22 and the like, and the hydraulic oil guided to the arm cylinder 8 can be cooled, and the same effect as the first embodiment. Can be obtained.

Further, the embodiments described above, the heat radiating fin 20, but the upper portion or the outer peripheral portion of the 30 are in the configuration in which the friction reducing member, smooth protective cover 22 etc. by only the heat radiation fins 20, 30 is a guide member If it is possible to guide, it may be configured not to include the friction reducing member.

In the first and second embodiments, the curved surface portions 20a and 30a are formed at the end portions of the radiation fins 20 and 30, but a tapered portion may be provided instead of the curved surface portions 20a and 30a. Yes.

  In the first and second embodiments, three radiating fins 20 and 30 are provided on the outer peripheral surface of the cylinder tube 8a. However, these may be provided at equal intervals or at different intervals. Good. Furthermore, the number of each of the heat radiating fins 20 and 30 is not limited to three, and may be four or more. Moreover, each of the radiation fins 20 and 30 may be provided in the same shape, or may be provided so as to have different width dimensions.

DESCRIPTION OF SYMBOLS 1 Traveling body 2 Revolving body 3 Working apparatus 5 Arm 8 Arm cylinder 8a Cylinder tube 8b Cylinder rod 11 Control valve 14 Hydraulic oil tank 15 Oil cooler 19 Pipe line 20 Radiation fin 20a Curved surface part 21 Friction reduction member 22 Protective cover 22a Hook part 23 protective cover 24 the protective cover 30 radiating fins 30a curved portion

Claims (5)

A protective cover for protecting a cylinder rod included in the hydraulic cylinder is provided in a working machine having a hydraulic cylinder that drives the working device and an oil cooler that cools the hydraulic oil that is discharged from the hydraulic cylinder and guided to the hydraulic oil tank. In the cylinder rod protection structure that is attached to the cylinder rod and moved together with the cylinder rod,
Provided between the cylinder tube of the hydraulic cylinder, in which the cylinder rod is accommodated so as to be able to advance and retreat, and the protective cover, are radiating fins composed of a plurality of plate-like members extending along the extending direction of the protective cover. ,
A cylinder rod protection structure characterized in that a curved surface portion or a taper portion is formed at each of an end portion located on the side closer to the cylinder rod of the radiating fin and an end portion located on the side far from the cylinder rod. . In the cylinder rod protection structure according to claim 1,
A cylinder rod protection structure, wherein the heat dissipating fins are provided on an outer peripheral surface of the cylinder tube. In the cylinder rod protection structure according to claim 2,
The heat dissipation fins, cylinder rod protective structure, characterized in that also serves as a guide member for guiding the protective cover that moves on Symbol cylinder rod and integrally. In the cylinder rod protection structure according to claim 3,
A cylinder rod protection structure, wherein a friction reducing member is provided between the radiation fin and the protective cover. In the cylinder rod protection structure according to any one of claims 1 to 4,
The protective cover has a cross-sectional shape in a direction orthogonal to an extending direction thereof, which is an arc shape surrounding the cylinder rod.

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