JP2010116690A - Device for lifting and lowering cab of working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit the shake of a cab by increasing the supporting strength of a whole parallel link mechanism for a lifting/lowering operation including upper and lower links. <P>SOLUTION: In this device for lifting and lowering the cab 32 of a working machine, a connecting bracket 41 is supported on upper turning body 24 in such a manner as to be movable forward and backward, while a base 50 for mounting the cab 32 is supported so as to be ascended and descended on the connecting bracket 41 via the parallel link mechanism 43 for the lifting/lowering operation and a cylinder 55 for the lifting/lowering operation. An upper end of a reinforcing bracket 51 is pivoted and connected to an intermediate portion of the upper link 44 of the parallel link mechanism 43, whereby a lower end of the reinforcing bracket 51 is pivoted and connected to an intermediate portion of the lower link 45 of the parallel link mechanism 43. Additionally, the cylinder 55 is interposed between the intermediate portion of the reinforcing bracket 51 and the connecting bracket 41, so that the rigidity of the whole parallel link mechanism 43 can be increased. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cab elevating device for a working machine, and more particularly to a cab elevating device for a working machine in which a cab is provided so as to be movable up and down via a parallel link mechanism.

  Conventionally, this kind of work machine used for construction work, harbor cargo handling work, etc. has an upper swing body mounted on the lower traveling body so as to be able to swing, and a parallel link mechanism for longitudinal movement at the front part of the upper swing body Further, the connection bracket is provided so as to be movable in the front-rear direction via the forward / backward movement cylinder. As shown in FIG. 4, a mount 4 for mounting the cab 3 is provided on the connection bracket 1 via a lifting / lowering parallel link mechanism 2 so as to be movable up and down, and connected to the lifting / lowering parallel link mechanism 2. A lifting cylinder 5 is interposed between the bracket 1 and the bracket 1.

Thus, when the elevating cylinder 5 and the longitudinal cylinder are extended and contracted, the cab 3 moves in the vertical direction and the longitudinal direction via the elevating parallel link mechanism 2 and the longitudinal link parallel link mechanism (not shown) ( Patent Document 1).
JP 2001-260952 A

  In the conventional cab elevating device, the elevating parallel link mechanism 2 includes an upper link 6 and a lower link 11 facing each other, and an upper end portion of the elevating cylinder 5 is pivotally connected to an intermediate portion of the upper link 6 via a pin 7. In addition, the lower end of the lifting cylinder 5 is pivotally connected to the connection bracket 1 via a pin 8.

  For this reason, a triangle is formed by connecting the three points of the pins 7 and 8 on both the upper and lower ends of the lifting cylinder 5 and the lower end pin 9 of the upper link 6, and the constituent parts of the triangle have high rigidity as a whole. Therefore, since the support strength of the upper end side pin 10 of the upper link 6 that supports the cab 3 is increased, the support force of the cab 3 by the upper end side pin 10 is sufficiently ensured.

  On the other hand, the lower link 11 of the lifting / lowering parallel link mechanism 2 is not pivotally connected to the upper end of the lifting / lowering cylinder 5, so that the support strength of the upper end side pin 12 of the lower link 11 does not increase. As a result, the support force of the cab 3 by the upper end side pin 12 is not sufficient, and there is a problem that the support stability of the cab 3 is lowered and the cab 3 is easily shaken when the cab 3 is moved up and down.

  Therefore, there is a technical problem to be solved in order to increase the overall support strength of the lifting / lowering parallel link mechanism including the upper link and the lower link and to suppress the swaying of the cab. The purpose is to solve.

The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is such that the connection bracket is supported on the upper swing body so as to be movable back and forth, and is used for raising and lowering on the connection bracket. In a cab lifting device for a work machine in which a cab mounting base is supported so as to be movable up and down via a parallel link mechanism and a lifting cylinder, an upper end portion of a reinforcing bracket is attached to an intermediate portion of the upper link of the lifting and lowering parallel link mechanism. While pivotally connecting, the lower end portion of the reinforcing bracket is pivotally connected to the middle portion of the lower link of the lifting / lowering parallel link mechanism, and the lifting bracket is connected between the middle portion of the reinforcing bracket and the connection bracket. There is provided a cab elevating device for a working machine, characterized in that, by interposing a cylinder, the rigidity of the elevating / lowering parallel link mechanism is increased.

  According to this configuration, the middle portion of the upper link and the middle portion of the lower link are pivotally connected via the reinforcing bracket, and the middle portion of the reinforcing bracket is supported by the lifting cylinder. The Therefore, a quadrangular shape is formed by connecting four points, that is, the upper end side pivot support point of the upper link, the upper end side pivot support point of the lower link, and the upper and lower end side pivot support points of the reinforcing bracket.

  A downward force due to the weight of the cab acts on the rectangular component, and the downward force is received by the lifting cylinder. Therefore, the lifting parallel link including the upper link and the lower link is provided. The rigidity of the entire mechanism is increased. As a result, the support strength of the upper end side pivot support points of both the upper link and the lower link that support the cab increases.

  According to the first aspect of the present invention, the support strength of the upper link on the upper link as well as the upper link on the upper link is increased, so that the cab can be sufficiently supported by the upper and lower links. Thus, since the support stability at the time of raising and lowering the cab is improved, it is possible to reliably suppress the cab shake as in the conventional example.

  The present invention achieves the purpose of increasing the overall support strength of the lifting and lowering parallel link mechanism including the upper link and the lower link to suppress the cab swing, so that the connection bracket can be moved back and forth on the upper swing body. In the cab elevating device of a work machine supported and supported by the connecting bracket through a lifting / lowering parallel link mechanism and a lifting / lowering cylinder on the connection bracket, the lifting / lowering parallel link mechanism The upper end of the reinforcing bracket is pivotally connected to the middle portion of the upper link, and the lower end of the reinforcing bracket is pivotally connected to the middle portion of the lower link of the lifting / lowering parallel link mechanism. By inserting the lifting cylinder between the intermediate portion and the connection bracket, the rigidity of the lifting and lowering parallel link mechanism is increased. Was realized by the form was.

  A preferred embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a hydraulic excavator 21 as a working machine according to the present embodiment. As shown in the figure, an upper swing body 24 is mounted on the lower traveling body 22 via a swing mechanism 23 so that the upper swing body 24 can swing, and a boom 25 can be rotated up and down on one side of the front portion of the upper swing body 24. It is connected to. An arm 26 is pivotally attached to the tip of the boom 25 so as to be rotatable up and down.

  Further, an end attachment (lifting magnet or bucket) 27 is swingably attached to the tip of the arm 26. Reference numerals 28, 29 and 30 in the figure are cylinders for driving the boom 25, the arm 26 and the end attachment 27, respectively.

  A cab 32 is provided at the front other side of the upper swing body 24 so as to be movable in the front-rear direction and the vertical direction via a parallel link mechanism and a cylinder. Next, the cab lifting device according to the present embodiment will be described in detail.

A support bracket 33 is fixed to the front portion of the upper swing body 24, and a first parallel link mechanism (a parallel link mechanism for back and forth movement) 34 is mounted on the support bracket 33 so as to be vertically rotatable. The first parallel link mechanism 34 includes a pair of front and rear front links 35 and a rear link 36, and the front link 35 and the rear link 36 are spaced apart from each other in parallel in the front-rear direction (the left-right direction in FIG. 1).

  Lower ends of the front link 35 and the rear link 36 are pivotally attached to the support bracket 33 via lower pins 37 and 38, respectively. The upper ends of the front link 35 and the rear link 36 are pivotally attached to the connection bracket 41 via upper pins 39 and pins 40, respectively.

  Further, a first cylinder (front / rear movement cylinder) 42 is interposed between the connection bracket 41 and the support bracket 33. Therefore, when the first cylinder 42 is driven to extend and contract, the connection bracket 41 rotates in the front-rear direction via the first parallel link mechanism 34.

  Further, a second parallel link mechanism (elevating / lowering parallel link mechanism) 43 is mounted on the connection bracket 41 so as to be vertically rotatable. The second parallel link mechanism 43 has a pair of upper and lower upper links 44 and a lower link 45, and the upper link 44 and the lower link 45 are spaced apart from each other in parallel in the vertical direction.

  The lower ends of the upper link 44 and the lower link 45 are pivotally attached to the connection bracket 41 via lower pins 46 and 47, respectively. Further, the upper ends of the upper link 44 and the lower link 45 are pivotally attached to the rear end portion (upward bent end portion) of the mount 50 for mounting the cab 32 via the upper pin 48 and the pin 49, respectively.

  As illustrated in FIG. 2, the upper end portion of the reinforcing bracket 51 is pivotally attached to the intermediate portion of the upper link 44 via a pin 52, and the lower end portion of the reinforcing bracket 51 is connected to the lower link 45 via a pin 53. It is pivotally attached to the middle part.

  Further, an upper end portion of a second cylinder (lifting / lowering cylinder) 55 is pivotally attached to an intermediate portion of the reinforcing bracket 51 via a pin 54, and a lower end portion of the second cylinder 55 is pivoted to the connection bracket 41 via a pin 56. It is worn. Therefore, when the second cylinder 55 is driven to extend and contract, the gantry 50 rotates in the vertical direction via the second parallel link mechanism 43.

  In the cab lifting and lowering device having the above configuration, the intermediate portion of the upper link 44 and the intermediate portion of the lower link 45 of the second parallel link mechanism 43 are pivotally connected via a reinforcing bracket 51. Further, the intermediate portion of the reinforcing bracket 51 and the connection bracket 41 are pivotally connected via a second cylinder 55.

  Therefore, the upper end side pin 48 of the upper link 44 and the upper end side pin of the lower link 45 and the four points of the upper and lower end side pins 52 and 53 of the reinforcing bracket 51 are connected by a two-dot chain line in FIG. As illustrated, a rectangular ABCD, more specifically, a parallelogram having a pair of horizontal sides and a pair of vertical sides facing each other is formed.

  A downward force is applied to the connection bracket 41 by the weight of the cab 32 on the components of the parallelogram ABCD. In this case, the downward force acting on the connection bracket 41 is received by the second cylinder 55 that supports the connection bracket 41. For this reason, the upper link 44, the lower link 45, and the reinforcing bracket 51 that constitute the parallelogram ABCD generate a tensile force that reinforces the mutual coupling force.

  Accordingly, the rigidity of the entire second parallel link mechanism 43 including the upper link 44 and the lower link 45 is increased, and as a result, the support strength of the upper end side pin 48 of the upper link 44 and the upper end side pin 49 of the lower link 45 is remarkably increased. To do.

As described above, according to the present invention, the support strength of not only the upper end side pin 48 of the upper link 44 but also the upper end side pin 49 of the lower link 45 is increased, so that the support force of the cab 32 by the upper link 44 and the lower link 45 is increased. Sufficiently secured.

  Thus, the stability of supporting the cab 32 by the pair of front and rear upper end side pins 48 and 49 is improved, so that the shaking of the cab 32 during the raising / lowering operation can be reliably suppressed.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

The side view of the working machine which shows one Example of this invention and mounts a cab raising / lowering apparatus. The enlarged view which shows the principal part of the cab raising / lowering apparatus which concerns on this invention. The expanded explanatory view which illustrates the structure of the quadrangle part of the 2nd parallel link mechanism of the cab raising and lowering device of Drawing 3. The side view which shows the principal part of the cab raising / lowering apparatus which concerns on a prior art example.

Explanation of symbols

21 Excavator (work machine)
24 Upper swing body 32 Cab 34 First parallel link mechanism (parallel link mechanism for back and forth movement)
41 Connection bracket 42 1st cylinder (Cylinder for longitudinal movement)
43 Second parallel link mechanism (parallel link mechanism for lifting and lowering)
44 Upper link 45 Lower link 46 to 49 Pin 50 Mounting base 51 Reinforcement bracket 52 to 54 Pin 55 Second cylinder (cylinder for lifting)
56 pins

Claims (1)

A work machine in which a connection bracket is supported on the upper swing body so as to be movable back and forth, and a cab mounting base is supported on the connection bracket so as to be movable up and down via a parallel link mechanism for lifting and lowering and a cylinder for lifting and lowering. In the cab lifting and lowering device,
The upper end portion of the reinforcing bracket is pivotally connected to the middle portion of the upper link of the lifting / lowering parallel link mechanism, and the lower end portion of the reinforcing bracket is pivotally connected to the middle portion of the lower link of the lifting / lowering parallel link mechanism, Further, the working machine is configured to increase rigidity of the lifting / lowering parallel link mechanism by interposing the lifting / lowering cylinder between an intermediate portion of the reinforcing bracket and the connection bracket. Cab lifting device.

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