JP3891514B2 - Construction machinery cab support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a support device for a cab for a cab installed in a construction machine such as a hydraulic excavator or a work vehicle.
[0002]
[Prior art]
FIG. 10 is a cross-sectional view showing an example of the vibration isolator described in Japanese Utility Model Laid-Open No. 2-45881. FIG. 11 is a principle diagram of the vibration isolator shown in FIG. In FIG. 11, reference numeral 1 denotes a platform, and 4 denotes a driver's cab, between which an elastic rubber 5 a having two spring constants k 1 and an elastic rubber 5 b having a spring constant k 2 are attached. A damper 6 is provided separately from the elastic rubbers 5a and 5b. Reference numeral 13 denotes a box, which is fixed on the platform 1 by a bracket 14, and the upper part is attached to the cab 4 by bolts 16 via an elastic rubber 15 having a spring constant k3. Since it is configured as described above, the spring 5c having a relatively low spring constant k3 (the spring 5c in FIG. 11 is the same as the elastic rubber 15 in FIG. 10) and the damper 6 are used as a countermeasure against resonance during high-speed running. In addition, when riding on a stone during traveling or sudden shock during excavation, a zone in which a large spring constant k1 or k2 acts is used, so that the riding comfort at high speed is improved, Large displacement due to sudden shock during excavation can be prevented.
[0003]
FIG. 12 is a cross-sectional view of an essential part showing a support structure of an embodiment cab 18 described in Japanese Patent Laid-Open No. 3-96527. In the support structure shown in FIG. 12, the front left and right sides of the cab 18 are supported by four buffer supports 9 ′, 10 ′, 11 ′, and 12 ′ disposed on the frame 33 of the upper swing body 34. Support members 22 and 23 are provided at positions on both sides of the rear side of the cab of the frame 33, and the support members 22 and 23 are cushioned near the center of gravity of the cab 18 (the center of gravity G exists at a height H from the upper surface of the floor plate 21). The support members 24 and 25 are used for support.
[0004]
[Problems to be solved by the invention]
In the vibration isolator of one embodiment of the prior art shown in FIGS. 10 and 11, as a countermeasure against resonance when the construction machine is traveling at high speed, the spring 5c and the damper 6 having a relatively low spring constant k3 are used to operate at high speed. The resonance of the chamber 4 is prevented, the ride comfort at high speed is improved, and the spring constant k1 (spring 5a) or k2 (spring 5b) is set when climbing on a stone during traveling or sudden shock during excavation. A working zone is used to prevent large displacement. However, the arrangement of the springs 5a, 5b, 5c and the damper 6 with respect to the platform 1 is not described. Usually, the platform 1 is formed in a cantilevered state (so-called overhanging state) with the center portion of the vehicle body as a fulcrum, so each placement position of the platform 1 on which the springs 5a, 5b, 5c and the damper 6 are placed. The values of the spring constants of the parts with respect to the central part of the vehicle body are different from each other. For this purpose, when a buffering spring or damper is arranged at each of the arrangement positions, the spring constants of a plurality of support parts supporting the cab 4 have various values. Therefore, when the construction machine is traveling or excavating, unbalanced vibrations act on the support portions, and displacement that causes the cab 4 to be distorted is generated. Since the structural strength of the cab 4 is adversely affected and the cab 4 is damaged, it is very bad for maintenance.
[0005]
Further, in the support structure of the cab 18 of one embodiment of the prior art shown in FIG. 12, each of the six buffer supports 9 'to 12', 24, 25 having the same shape and structure is provided with the frame 33 and the elastic rubber. The support members 22 and 23 are arranged at a total of six positions. Although the spring constants of the buffer supports 9 ′ to 12 ′, 24, and 25 are all considered to be the same value, the frame 33 and the support members 22 and 23 have a total of six arrangement portions with respect to the center of the vehicle body. Each spring constant is different. Therefore, in the case of the support structure of the cab 18, the same operation as that of the vibration isolator shown in FIGS. 10 and 11 is performed, so that the condition of the structure of the cab 18 is very poor. The present invention provides a cab support device for a construction machine that improves the structural maintainability of a cab for a cab by providing all of the support portions at a plurality of locations that support the cab all with the same spring constant. The purpose is to provide.
[0006]
[Means for Solving the Problems]
A plurality of cushioning supports disposed on the structure, and a cab mounted on the structure via the plurality of cushioning supports, and the plurality of cushioning supports. A structure spring constant that the structure itself is supported in a cantilevered manner from a fulcrum set on the upper revolving body at the position of each of the buffer supports, and a buffer that each of the plurality of buffer supports has The total value of each of the support spring constants is the spring constant for cab buffering at each of the buffer support positions, and the cab buffer spring constant at each of the plurality of buffer support positions is substantially constant. Thus, at least one of the structural body spring constant and the buffer support spring constant is adjusted and set.
[0007]
In the structure mounted with the cab of the upper revolving structure, the spring constant of the structure itself becomes lower as the distance from the fulcrum (distance from the rigid body or distance from the slewing bearing) decreases. The shorter the distance, the higher the spring constant. By grasping this structure spring constant, the spring constant of the buffer support that supports the cab and the total spring constant of the structure is regarded as the spring constant for cab buffering, so that the position of each buffer support is determined. An appropriate spring constant for buffering and supporting the cab can be obtained. It is possible to set a spring constant considering the weight balance of the cab itself and the vibration characteristics of the construction machine. The spring constant can be adjusted easily and reliably by adjusting the rigidity of the structure or by appropriately using a buffer support having a different spring constant. In particular, if the spring constants for cab cushioning at the positions where the plurality of cushioning supports are arranged are substantially the same, when the construction machine travels or excavates, the support parts of the cab can be balanced. Therefore, the distortion of the cab can be minimized.
[0008]
In addition, a plurality of cushioning supports having different elastic characteristics are set, and these are used selectively. Accordingly, the present invention can be applied even to other models having different structures. Moreover, if a buffer support having vibration damping properties is set as an elastic characteristic, a more appropriate buffer effect can be obtained. More specifically, in the case where elastic rubber is used as the buffer member of the buffer support, the spring constant of the elastic rubber is changed, and as the buffer support, liquid is sealed inside the casing so that the vibration damping property is reduced. In the damper exhibiting the above, the setting can be easily performed by changing the spring constant, and a buffer support body having a plurality of elastic characteristics can be obtained.
[0009]
Further, by grasping the structure as a cantilever supported by the pivot bearing of the upper swing body as a fulcrum, the elastic characteristics of the entire upper swing body can be taken into consideration, and vibrations acting on the cab can be balanced. Can be good. Further, when the structure body is a deck portion composed of a plate-like member, and the plurality of buffer support members are respectively arranged on the deck portion, the difference depending on the distance from the fulcrum of the spring constant of the deck portion becomes large. Therefore, the above effect of the present invention can be obtained more remarkably. This includes the case where the entire frame of the upper swing body is formed of a plate material.
[0010]
Usually, the cab for the operator's cab is attached to a deck portion of a swing frame that is a structure of the upper swing body through a plurality of buffer supports (for example, four locations, six locations, etc.). In this case, the spring constant with the vehicle body central portion as the fulcrum of the arrangement position portion that is the farthest away from the vehicle body central portion among the plurality of arrangement position portions for the buffer support in the deck portion is the lowest ( small). On the other hand, the spring constant with the fulcrum at the center of the vehicle body is the highest (large) at the disposition position portion closest to the vehicle body center. Therefore, a buffer support body having a large spring constant is provided for a placement position portion having a small spring constant among a plurality of placement position portions of the deck portion, and a buffer support having a small spring constant for a placement position portion having a large spring constant. By arranging each body, the structure spring constants of the respective arrangement position portions and the respective values obtained by adding the buffer support spring constants of the respective buffer support bodies arranged at the respective arrangement position portions are respectively equal. It becomes the value of. Therefore, when a construction machine equipped with the cab support device of the present invention travels or excavates, balanced vibrations act on each support portion of the cab, so that the distortion shape of the cab can be minimized. It is. Further, each value obtained by adding the structure spring constant of each arrangement position portion and the buffer support spring constant of each buffer support member arranged at each arrangement position portion, the weight balance of the cab itself, or construction In some cases, the ride comfort can be further improved by setting the value with a change in consideration of the vibration characteristics of the machine.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a left side view of a hydraulic excavator provided with a cab support device according to an embodiment of the present invention. In the figure, 2 is a lower traveling body of a hydraulic excavator, 3 is an upper revolving body connected to the upper part of the lower traveling body 2 via a swivel bearing 7, and 8 is a revolving frame which is a structure of the upper revolving body 3 (illustrated). Deck unit 17, which will be described later, 17 is a driver's cab mounted above deck unit 8, 19 is a cab constituting operator cab 17, and 20 is a work attachment attached to the front of upper revolving unit 3. It is. FIG. 2 is a right side view of the excavator in FIG. As shown in FIG. 2, the front end of the deck portion 8 is formed to protrude forward by a dimension Y from the right front end i of the upper swing body 3. FIG. 3 is a plan view of the excavator in FIG. FIG. 4 is a plan view showing a turning frame 26 of the upper turning body 3 of the excavator in FIG. In the drawing, a, b, c, and d are arrangement position portions provided on the deck portion 8 of the swivel frame 26 for attaching a plurality of buffer supports (four in this embodiment) to be described later. . FIG. 5 is a left side view of the main part as viewed from A of FIG.
[0012]
FIG. 6 is a cross-sectional view showing the buffer support 27 according to an embodiment in a state of being arranged at any of the arrangement positions a, b, c, and d in FIG. In the figure, 28 is a support plate for the cab 19, 29 is a mounting plate for the buffer support 27, 30 and 30 ′ are elastic rubbers each serving as a buffer member, 31 is a cover fitting, and 32 is a bolt. FIG. 7 is a principle diagram of FIG. FIG. 8 is a cross-sectional view showing a buffer support 35 according to another embodiment in a state of being arranged at any one of the arrangement positions a, b, c, and d in FIG. In the figure, 28 is a support plate for the cab 19, 29 ′ is a mounting plate for the buffer support 35, 36 is a casing for the buffer support 35, 37 is a vertical shaft provided at the axial center of the casing 36, 38 is Elastic rubber connecting the vertical shaft 37 to the casing 36, 39 a damper in which a highly viscous liquid such as silicon oil is sealed inside the casing 36, and 40 a damper attached to the lower end of the vertical shaft 37 Reference numeral 39 denotes a vibration attenuating plate; 41, an orifice opened in the vibration attenuating plate 40; and 42, a bolt that fixes the vertical shaft 37 and the support plate. FIG. 9 is a principle diagram of FIG.
[0013]
Next, the structure of the cab support device of this embodiment will be described with reference to FIGS. In the present embodiment, a plurality of (four in this embodiment) buffer supports (four buffer supports 27 shown in FIG. 6) may be used for the deck portion 8 of the swing frame 26 of the upper swing body 3. In addition, the four buffer support members 35 shown in FIG. 8 may be used, or the buffer support members 27 and 35 may be combined to form a total of four). , C, d (shown in FIG. 4), and in the excavator in which the cab 19 for the cab 17 is mounted on the deck portion 8 through the four buffer supports, the upper swing body 3 The spring constants (kfa, kfb, kfc, kfd) of the respective arrangement position portions a, b, c, d of the deck portion 8 with the slewing bearing 7 on the bottom surface of the deck portion 8 as a fulcrum are respectively obtained (by structural vibration analysis means) ), Spring constants kf (bars) of the arrangement position portions a, b, c, d. The constants are kfa, kfb, kfc, and kfd, respectively. However, for convenience of explanation, the constants are kf), and each of the buffer supports arranged at the respective arrangement positions a, b, c, and d. Each value obtained by adding the spring constant (the spring constant of the buffer support 27 is km and the spring constant of the buffer support 35 is km ′) is set to be an equivalent value ko. In this case, the spring constant of the elastic rubber is different from that of the elastic rubber (30, 30 ', 38) as the buffer member of the buffer support (27, 35) In some cases, they may be the same, but they are also included.) As the buffer support (35), a damper 39 in which liquid is enclosed in the casing 36 to exhibit vibration damping is provided. The spring constant of the damper 39 was set to be different from that used.
[0014]
Next, the operation of the cab support device of this embodiment will be described. In the present embodiment, the cab 19 is attached to the deck portion 8 of the revolving frame 26 via four buffer supports (27 or 35). In this case, of the four arrangement position parts a, b, c, d in the deck part 8, the slewing bearing 7 of the arrangement position part a that is the most distant from the slewing bearing 7 in the center of the vehicle body is a fulcrum. The spring constant is the smallest. On the contrary, the spring constant with the slewing bearing 7 as a fulcrum of the disposition position portion d that is closest to the slewing bearing 7 is the largest. Therefore, of the arrangement parts a, b, c and d, a buffer support body having a large spring constant is provided for an arrangement position part having a large spring constant, and a buffer support having a small spring constant is provided for an arrangement position part having a large spring constant. By arranging the bodies, the spring constants of the arrangement parts a, b, c, and d (the spring constants are kfa, kfb, kfc, and kfd, respectively, but in FIG. 7 and FIG. And the respective values obtained by adding the spring constants km or km ′ of the buffer supports 27 or 35 arranged at the arrangement position portions a, b, c, d respectively become equivalent values ko. . In addition, the thing using elastic rubber (30, 30 ', 38) as a buffer member of each said buffer support body (27, 35) is made to change the spring constant of said elastic rubber (30, 30', 38), Further, in the damper 39 as the buffer support (35) in which the liquid is enclosed in the casing 36 to exhibit vibration damping, the spring constant ko is easily set by changing the spring constant. be able to. Therefore, when a hydraulic excavator equipped with the cab support device of the present invention travels or excavates, balanced vibrations act on each support portion of the cab 19 (support portion of the support plate 28 shown in FIGS. 6 and 8). As a result, the distorted shape of the cab 19 can be minimized. That is, since the impact generated during excavation during excavation does not adversely affect the structural strength of the cab 19, the structural maintainability of the cab 19 can be improved.
[0015]
【The invention's effect】
When a construction machine equipped with the cab support device of the present invention travels or excavates, balanced vibrations act on each support portion of the cab, so that the distorted shape of the cab can be minimized. In other words, since the shock generated during excavation during construction machinery does not adversely affect the structural strength of the cab, it is possible to improve the structural maintenance of the cab. The ride quality can also be improved.
[Brief description of the drawings]
FIG. 1 is a left side view of a hydraulic excavator provided with a cab support device according to an embodiment of the present invention.
2 is a right side view of the excavator in FIG. 1. FIG.
3 is a plan view of the excavator in FIG. 1. FIG.
4 is a plan view showing a swing frame of an upper swing body of the hydraulic excavator in FIG. 1. FIG.
5 is a left side view of the main part as viewed from A of FIG.
6 is a cross-sectional view showing a buffer support according to an embodiment in a state of being arranged at any of the arrangement positions in FIG.
FIG. 7 is a principle diagram of FIG. 6;
FIG. 8 is a cross-sectional view showing a buffer support body according to another embodiment in a state of being arranged at any of the arrangement position portions in FIG.
FIG. 9 is a principle diagram of FIG. 8;
FIG. 10 is a cross-sectional view showing a vibration isolator according to an embodiment of the prior art.
FIG. 11 is a principle view of the vibration isolator shown in FIG.
FIG. 12 is a cross-sectional view of an essential part showing a support structure for a driver's cab according to an embodiment of the prior art.
[Explanation of symbols]
3, 34 Upper revolving body 4, 17, 18 Cab 5a, 5b, 15, 30, 30 ', 38 Elastic rubber 6, 39 Damper 7 Swivel bearing 8 Deck portion 9', 10 ', 11', 12 ', 24 , 25, 27, 35 Buffer support 19 Cab 26 Swivel frame 36 Casing a, b, c, d Arrangement position part

Claims (6)

A plurality of cushioning supports disposed on the structure, and a cab mounted on the structure via the plurality of cushioning supports, and the plurality of cushioning supports. A structure spring constant that the structure itself is supported in a cantilevered manner from a fulcrum set on the upper revolving body at the position of each of the buffer supports, and a buffer that each of the plurality of buffer supports has The total value of each of the support spring constants is set as the spring constant for cab buffering at each of the buffer support positions, and the cab buffer spring constant at each of the plurality of buffer support positions is substantially the same . Thus, a cab support device for a construction machine, wherein at least one of the structural body spring constant and the buffer support spring constant is adjusted and set. Before Kiyuru opposition support those are plural sets having different elastic properties, construction machine cab supporting apparatus according to claim 1, characterized in that so as to selectively use it.   The cab support device for a construction machine according to claim 2, wherein elastic rubbers having different elastic coefficients are set as the buffer members of the plurality of buffer supports.   3. The damper according to claim 2, wherein the plurality of buffer supports include spring members having different spring constants, and a damper is provided in which liquid is sealed in the casing so as to exhibit vibration damping. A cab support device for construction machinery. The cab support device for a construction machine according to any one of claims 1 to 4, wherein the structure is supported by a swing bearing of the upper swing body as a fulcrum. The construction according to any one of claims 1 to 5, wherein the structural body is a deck portion configured by a plate-like member, and the plurality of buffer supports are respectively disposed on the deck portion. Machine cab support device.

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