JP2005145182A - Construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction machine securing the safety of an operator in an operator's cabin by protecting the operator's cabin even if the construction machine turned over. <P>SOLUTION: In this construction machine such as a hydraulic shovel having a swing frame 1 and the operator's cab installed on the swing frame 1, a protective structure 3 for the operator's cab for preventing the operator's cab 2 from receiving a direct impact when the construction machine is turned over is installed on the upper surface part 2a of the operator's cabin 2. The rear end part of the protective structure 3 for the operator's cabin is supported by a column 4a installed on the swing frame 1. A support body 5 supporting the front end part of the protective structure 3 for the operator's cab when the protective structure 3 for the operator's cab receives impact by the overturning of the construction machine is installed above the upper end part of a front pillar 2b between the upper surface part 2a of the operator's cabin 2 and the protective structure 3 for the operator's seat. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a self-propelled construction machine such as a hydraulic excavator provided with a revolving frame and a cab installed on the revolving frame.

  A self-propelled construction machine such as a hydraulic excavator has a lower traveling body such as a crawler for enabling the self-propelled construction machine to travel, and an upper revolving body installed on the lower traveling body so as to be able to swivel. Provided and configured. This upper revolving structure is configured by installing various devices such as a driver's cab, a machine room, and a counterweight on a revolving frame that is a base of the upper revolving structure. At the front end of the swivel frame, a boom that can tilt with respect to the swivel frame, an arm that can swing with respect to the boom, and an attachment such as a bucket that can swing with respect to the arm and perform various operations. The equipped working device (front) is usually installed. For example, in a hydraulic excavator, such a working device is installed on the right side in the traveling direction of the swivel frame, so that the operator's cab is installed close to the left limit of the swivel frame. According to the present invention, in such a construction machine, when the construction machine falls, the operator's cab is protected so that the operator can be safe.

  In this specification, the operator's cab refers to a partition that partitions the operator's operating space, and is also referred to as a cab. When manufacturing the cab of this construction machine, for example, the left and right side portions are formed by joining a pair of steel plates, and the upper surface portion and the rear surface portion are formed by a single steel plate. And the steel plate used as the upper surface part of a driver's cab and the steel plate used as a rear surface part are attached to the upper end part and rear end part of each joining steel plate used as a side part on either side by welding, respectively. When the left and right side portions are formed by joining a pair of steel plates, a plurality of hollow columnar pillar portions extending in the vertical direction are formed between the pair of steel plates, and a steel pipe steel rod or the like is appropriately formed in the hollow portion of the pillar portion. A pillar is formed by loading a reinforcing material or a filler. This pillar increases the rigidity of the cab and plays a role as a vertical frame of the cab.

This pillar-shaped pillar is usually composed of a front pillar that forms a skeleton part at the front end of the cab, a center pillar that forms a skeleton part at the center, and a rear pillar that forms a skeleton part at the rear end. The pillars are respectively formed on the left and right side portions. A windshield is attached between the front pillars on the left and right side portions, and a door is attached between the front pillar and the center pillar on the left and right side portions so as to be openable and closable. In addition, a window is appropriately formed at predetermined positions of the left and right side plates and the rear plate, and glass or the like is attached thereto, and a bracket made of a rectangular frame is provided at the bottom of the left and right side plates and the rear plate. Install the floor board. The cab of the construction machine is formed so as to increase the rigidity of the cab as much as possible with the above structure, and is installed on the revolving frame via the vibration isolator. A construction machine provided with this type of cab is described in Patent Document 1, for example.
JP 2001-115491 A (page 3-6, FIG. 1-7)

  By the way, a construction machine using a crawler such as a hydraulic excavator has a performance capable of traveling even on a land with a considerably large slope. Therefore, there is a risk of overturning when working or moving on the slope. In addition, in such a construction machine, there is a case where a heavy load is lifted and swung, such as a work of hanging and transferring a suspended load by attaching an attachment. Construction machines such as hydraulic excavators have a risk of overturning when performing such operations.

  As a result, if the construction machine rolls over, the cab is located close to the limit on one side of the swivel frame, as described above, and the top of the side of the cab collides with the ground directly. Is subject to severe shock. Then, although the cab is formed so as to increase the rigidity, it may be greatly deformed by the impact. The deformation of the operator's cab due to such a fall becomes more severe as the model with a larger vehicle weight. If the driver's cab is directly impacted or greatly deformed in this way, it will naturally pose a danger to the operator operating in the cab. In addition, there is a risk that the door cannot be opened with the deformation of the cab and the operator cannot escape from the vehicle.

  The present invention was created to solve these problems, and its technical problem is that a construction machine that can protect the operator's cab and ensure the safety of the operator in the operator's cab even if it rolls over. Is to provide.

In order to achieve the above technical problem, the present invention
In a construction machine including a swivel frame and a cab installed on the swivel frame, a cab protection structure for preventing the cab from being directly impacted when the construction machine rolls over is provided at the top of the cab. When the rear side of this cab protection structure is supported by a support structure member installed on the swivel frame, and the cab protection structure is impacted by the rollover of the construction machine Support means capable of supporting the front side portion of the cab protection structure than the support structure member is provided between the top of the cab and the cab protection structure.

  Since the construction machine of the present invention employs such means, in the unlikely event that the construction machine rolls over, first, the cab protection structure on the top of the cab collides with the ground, and the collision occurs. The occupant's cab protection structure directly receives the impact at the time, and the impact can be prevented from being directly received by the cab as in the prior art. In that case, the load received by the cab protection structure due to such an impact is supported on the support structure member on the rear side of the cab protection structure and on the front side of the cab protection structure with respect to the support structure member. Since it is configured so that the driver's cab protection structure can be supported by both while being dispersed and transmitted appropriately to the support means, the cab can be operated without increasing the strength of the support structure member. The protective structural body can be reliably supported.

  The load caused by the impact is transmitted to the support means and applied to the cab. However, the load is transmitted to the support structure member in addition to the support means and is distributed and transmitted, so that it is remarkably large in the cab. Thus, it is possible to prevent the driver's cab from being greatly deformed as in the prior art. Therefore, the construction machine of the present invention can protect the operator's cab and ensure the safety of the operator in the operator's cab. In addition, in the construction machine of the present invention, the front side portion of the cab protection structure is supported by a support structure member that closes the space in the height direction of the cab like the rear side. Without the support means provided between the top of the cab and the cab protection structure, so that the front side of the cab protection structure is also supported by the support structure member. The front view is not disturbed.

  As will be apparent from the following description, the construction machine of the present invention employs the means described in the above section [Means for Solving the Problems]. It is possible to protect the operator's safety in the cab. In addition, while exhibiting such excellent effects, the support on the front side of the cab protection structure is particularly provided by the support means provided between the top of the cab and the cab protection structure. By doing so, the forward field of view is not obstructed by something like a support structure member during driving.

  When the construction machine of the present invention is embodied, particularly when embodied as in claim 2, the impact at the time of rollover of the construction machine is received mainly by the support structure member on the rear side of the cab protection structure. The support means for supporting the front side portion of the cab protection structure receives the impact as an auxiliary, so that the load applied to the cab due to the impact can be further reduced. The effect of protecting the operator's cab and ensuring the safety of the operator during rollover can be achieved more reliably. If the construction machine embodied in this way is further embodied as described in claim 3, in addition to exhibiting such effects, the impact received by the cab when the construction machine rolls over is buffered by an elastic body. This effect can be further promoted.

  When the construction machine according to the present invention is embodied, particularly as described in claim 4, the load applied to the cab through the support means when the construction machine rolls over is increased or decreased to increase the rigidity of the cab. Since it can be received by the upper end portion of the framing portion in the direction, it is not necessary to provide special reinforcing means for reinforcing the position of the cab that receives the load from the support means. Therefore, it is possible to secure the operator's cab while reducing the manufacturing cost of the construction machine and to ensure the safety of the operator in the operator's cab.

  Hereinafter, how the present invention is actually embodied will be described with reference to FIGS. 1 to 5 to clarify a desirable mode for carrying out the present invention.

  1 is a perspective view of essential parts of a construction machine according to a basic example embodying the present invention, FIG. 2 is a side view of essential parts of the construction machine of FIG. 1, and FIG. 3 embodies the present invention. FIG. 4 is an enlarged perspective view of another example of the support means in the construction machine, FIG. 4 is a vertical sectional view of the support means in FIG. 3, and FIG. 5 is a second view of the support means in the construction machine embodying the present invention. It is a vertical sectional view which expands and shows another example of.

  The construction machine of the example shown below that embodies the present invention is a crawler such as a hydraulic excavator provided with a turning frame and a driver's cab installed on the turning frame, like the construction machine according to the prior art described above. Is related to self-propelled construction machinery.

  First, based on FIG.1 and FIG.2, the general structure of the operator's cab of a construction machine and the matter relevant to this are demonstrated.

  In these drawings, reference numeral 1 denotes a revolving frame which is installed on the lower traveling body so as to be able to turn and serves as a base of the upper revolving body, 2 is a cab of a construction machine installed on the revolving frame 1, 2a is a cab 2 An upper surface portion of the cab 2 that forms the ceiling, 2b is a front pillar that is a skeleton portion of the front end portion of the cab 2, 2c is a center pillar that is a skeleton portion of the central portion of the cab 2, and 2d is a rear end of the cab 2. 2e is a side surface portion of the cab 2 formed by joining a pair of steel plates, 2f is a rear surface portion of the cab 2 formed by a single steel plate, and 2g is a front portion of the cab 2. A windshield, 2h is a door of the cab 2, and 6 is a vibration isolator for mitigating the vibration generated in the swivel frame 1 during the traveling and working of the self-propelled construction machine. It is.

  The turning frame 1 is turnably installed on a lower traveling body (not shown) by a crawler and can be turned by a hydraulic motor (not shown). Although not shown, a boom that can tilt with respect to the swing frame 1, an arm that can swing with respect to the boom, and a arm that can swing with respect to the boom are provided on the right side in the traveling direction of the front end of the swing frame 1. A working device having an attachment such as a bucket for performing various operations is installed. Therefore, the cab 2 is usually installed close to the left limit of the swivel frame 1. The driver's cab 2 is formed so as to be as hard to be deformed as possible by the structure described below for the safety of the operator.

  When the front pillar 2b, the center pillar 2c, and the rear pillar 2d are joined with a pair of steel plates to form the side surface portion 2e of the cab 2, a hollow columnar pillar portion extending from the upper end to the lower end is interposed between the pair of steel plates. It is formed so that the rigidity can be increased by appropriately forming a reinforcing material such as a steel pipe steel bar or a filler in the hollow portion of the pillar portion. In that case, each hollow pillar portion for forming the front pillar 2b and the rear pillar 2d is formed in a slightly curved shape so as to follow the shape of the front end and the rear end of the side surface portion of the cab 2, and the center pillar 2c. The hollow pillar portion for forming is formed linearly.

  The steel plates forming the upper surface portion 2a and the rear surface portion 2f of the cab 2 are attached to the upper end portion and the rear end portion of the steel plate forming the left and right side surface portions 2e of the cab 2 thus formed by welding, respectively. Openings and window portions for attaching the door 2h are formed in advance at predetermined positions of the left and right side surface portions 2e and the rear surface portion 2f, and a transparent plate such as glass is attached to the window portions. . A windshield 2g is attached between the front pillars 2b of the left and right side surface portions 2e, and a door 2h is pivotally attached to the center pillar 2c between the front pillar 2b and the center pillar 2c of the left and right side surface portions 2e. To attach the door 2h so that it can be opened and closed. Floor boards are attached to the bottoms of the left and right side surface portions 2e, the rear surface portion 2f, and the like in the assembly structure of the cab 2 thus formed in a box shape via a bracket (not shown) made of a rectangular frame. The cab 2 of the construction machine is formed so as to increase the rigidity of the cab 2 as much as possible with the above structure, and is installed on the revolving frame 1 via the vibration isolator 6.

  Next, characteristic items related to the construction machine of the present invention will be described with reference to FIGS.

  The construction machine shown in FIG.1 and FIG.2 shows the basic example which actualized this invention, 3 is a cab for preventing the cab 2 from receiving a direct impact at the time of a rollover of a construction machine. The protective structure 4a, 4b is a column as a support structure member for supporting the rear end of the cab protective structure 3, and the cab protective structure 3 is impacted by the rollover of the construction machine. It is a support body as a support means capable of supporting the front side portion of the driver's cab protection structure 3 with respect to the support columns 4a and 4b.

  The cab protection structure 3 is disposed on the upper surface 2a of the cab 2 and supported by the left and right support columns 4a and 4b only on the rear side, and this kind of support structure member is provided on the front side. I am trying not to. The left and right support columns 4a and 4b are arranged behind the cab 2 and are attached to the revolving frame 1 and the cab protection structure 3 by welding or by bolts via brackets. In the example shown here, the driver's cab protection structure 3 is supported by a pair of support columns 4a and 4b. However, another support column is provided between the pair of support columns 4a and 4b and is supported by more support columns. You may make it do. Further, instead of the support columns 4a and 4b, it may be supported by a plate extending in the vertical direction.

  The cab protection structure 3 is at least a cab close to the side of the swivel frame 1 so as to be able to receive an impact by contacting the ground prior to the cab 2 when the construction machine rolls over. The left side surface portion 2e is formed so as to slightly protrude outward from the left side surface portion 2e. Since the cab protection structure 3 is disposed on the upper surface 2a of the cab 2, the cab 2 can be used when working with a construction machine at a building demolition site or a quarry. It can also serve to protect the inside operator from falling objects. The driver's cab protection structure 3 can be supported only by both struts 4a and 4b if the strength (for example, thickness) of the left and right struts 4a and 4b is appropriately selected. In the example of 2, the support 5 can be shared and supported according to the rollover state of the construction machine, so that it is not necessary to increase the strength of the columns 4a and 4b.

  The support 5 is preferably configured to allow a certain degree of relative displacement of the cab 2 with respect to the cab protection structure 3. In the example of FIGS. 1 and 2, the support 5 is made of rubber, spring, oil, and the like. It is composed of an elastic body such as a damper. By configuring the support 5 with such an elastic body, the cab 2 can be displaced by a slight distance vertically and horizontally without being substantially restrained by the cab protection structure 3. Here, such support bodies 5 are provided on the left and right in the vicinity of the front end of the cab 2, and only the left side in the traveling direction appears in FIG. A support 5 is provided.

  In the example of FIGS. 1 and 2, when the support body 5 is provided between the top of the cab 2 and the cab protection structure 3, the upper end of the front pillar 2 b as a skeleton portion at the front end portion of the cab 2. The support 5 is provided above the upper end (above the region x where the front pillar 2b intersects the upper surface 2a of the cab 2). Instead of providing the support body 5 above the upper end portion of the front pillar 2b, the support body 5 is disposed above the upper end portion of the center pillar 2c (the region y where the center pillar 2c intersects the upper surface portion 2a of the cab 2). Or above the upper end of the rear pillar 2d (above the region z where the rear pillar 2d intersects the upper surface 2a of the cab 2). In addition to providing the support 5 above the upper end of the front pillar 2b, a similar support member 5 can be provided above the upper end of one or both of the center pillar 2c and the rear pillar 2d. However, it is preferable that the support 5 is provided above the upper ends of the pillars 2b, 2c, 2d so as to overlap the upper ends of the pillars 2b, 2c, 2d.

  The effects of the construction machine shown in FIGS. 1 and 2 having the above-described structure will be described.

  In this construction machine, the driver's cab protection structure 3 is formed so that the side part protrudes slightly outward from the left side face part 2e of the cab 2, so that it should roll over to the left in the event of a rollover. When this happens, the cab protection structure 3 on the upper surface 2a of the cab 2 first collides with the ground, and the cab protection structure 3 directly receives the impact at the time of the collision. Thus, it is possible to prevent the cab 2 from being directly received as in the prior art. When the vehicle rolls over to the right side, the right side surface portion 2e of the cab 2 is considerably separated from the right side portion of the swivel frame 1, and the working device ( Since the front) is installed, the cab 2 almost never collides with the ground.

  When the cab protection structure 3 collides with the ground and receives an impact, the cab protection structure 3 is mainly supported by the left and right columns 4a and 4b on the rear side, but the cab protection is provided by the impact. The support body 5 that supports the left and right support columns 4a and 4b on the rear side of the cab protection structure 3 and the front end portion of the cab protection structure 3 according to the state of the load. Since the driver's cab protection structure 3 can be supported in cooperation with the support columns 4a and 4b and the support body 5 while being dispersed and transmitted as appropriate, the support columns 4a and 4b Even if the strength is not increased, the cab protection structure 3 can be reliably supported.

  The load caused by the impact is transmitted to the support body 5 according to the fall state and applied to the cab 2 as well, but the load is transmitted to the support columns 5 and the columns 4a and 4b on the swivel frame 1 as well. As a result, the operator's cab 2 is prevented from being greatly deformed as in the prior art, and the operator's location is kept to a minimum. can do. Therefore, according to this construction machine, the operator's cab 2 can be protected by protecting the operator's cab 2.

  By the way, when supporting the cab protection structure 3, the rear side thereof is supported by the columns 4 a and 4 b, and the left and right front ends of the revolving frame 1 and the cab protection structure 3 are attached to the windshield 2 g. A method of supporting the front side of the driver's cab protection structure 3 with a support by connecting with a support along the front is also conceivable. However, when such a method is adopted, the left and right end portions of the windshield 2g are blocked by long pillars, so that the left and right front fields of the cab 2 are narrowed. On the other hand, in this construction machine, the support of the front side portion of the cab protection structure 3 is like support columns 4a and 4b that close the space in the height direction of the cab 3 like the rear side. Since it is performed by the support body 5 provided between the top of the cab 2 and the cab protection structure 3, the front side of the cab protection structure 3 is also supported by a support column. The front view is not disturbed as in the case of support.

  In this construction machine, the support body 5 is configured to allow the relative displacement of the cab 2 with respect to the cab protection structure 3 in particular. It is received by the support columns 4a and 4b on the rear side of the structure 3, and the support 5 on the front side of the cab protection structure 3 receives the impact as an auxiliary. Therefore, it is possible to further reduce the load applied to the cab 2 due to the impact at the time of the rollover of the construction machine, and more reliably achieve the effect of protecting the cab 2 and the safety of the operator at the time of the rollover of the construction machine. it can. In addition, since the support body 5 allows relative displacement of the cab 2 with respect to the cab protection structure 3, the original function of the vibration isolator 6 that alleviates transmission of vibration of the swivel frame 1 to the cab 2. Will not be damaged. Since the support 5 is composed of an elastic body such as rubber, a spring, and an oil damper, in addition to exhibiting such effects, the impact received by the cab 3 when the construction machine rolls over is caused by such an elastic body. These effects can be further promoted by buffering.

  When the support 5 is provided between the top of the cab 2 and the cab protection structure 3, the support 5 is provided above the upper end so as to overlap the upper end of the front pillar 2 b. Therefore, the load applied to the cab 2 through the support 5 when the construction machine rolls over can be received by the upper end portion of the front pillar 2b which is a vertical frame portion for increasing the rigidity of the cab 2. Therefore, it is not necessary to apply special reinforcing means for strengthening the location of the cab 2 that receives a load from the support body 5, so that the cab 2 can be reliably protected while reducing the manufacturing cost of the construction machine. The safety of the operator in the room 2 can be ensured.

  Finally, based on FIGS. 3 to 5, an example of another support means having the same function as the support body 5 in such a construction machine will be described.

  3 and 4 relating to this support means, the member 7 to be inserted having the insertion hole 7a into which the convex body 8a is inserted, and the convex body for insertion into the insertion hole 7a of the member 7 to be inserted. In this example, an insertion member 8 having 8a is provided to form a support 5 ′ as a support means. The member 7 to be inserted has a circular insertion hole 7a inside and has an annular shape, and the insertion member 8 has a disk-like mounting portion 8b at the base and a rod-like shape on the mounting portion 8b. A convex body 8a is projected. The insertion hole 7a of the inserted member 7 is slightly between the convex body 8a so that the convex body 8a can be displaced to some extent in the vertical and horizontal directions when the convex body 8a of the insertion member 8 is inserted. It is formed in the diameter which the gap | interval produces.

  In the example shown here, the member 7 to be inserted of the support 5 ′ thus configured is fixed to the upper surface 2 a side of the cab 2, and the insertion member 8 is fixed to the cab protection structure 3 side. However, both members 7 and 8 can be fixed in the opposite direction. In that case, the support 5 ′ is similar to the support 5 described above so that the inserted member 7 and the insertion member 8 of the support 5 ′ overlap the upper ends of the pillars 2b, 2c, 2d. It is desirable to provide it above the upper end.

  Since this support body 5 ′ has such a structure, when the cab protection structure 3 is impacted by the rollover of the construction machine, the lower surface of the mounting portion 8 b of the insertion member 8 is the surface of the inserted member 7. By contacting the upper surface, it is possible to support the front part of the driver's cab protection structure 3 with respect to the support columns 4a and 4b. Therefore, even when such a support 5 ′ is provided in place of the support 5 described above, the operator cab 2 can be protected and the operator in the operator cab 2 can be secured, and the like, as in the example described above. The effect of this can be achieved.

  Further, since the cab 2 is configured to allow relative displacement of the cab 2 with respect to the cab protection structure 3, the load applied to the cab 2 due to the impact when the construction machine rolls over, as in the example described above. Can be further reduced, and the effect of protecting the cab 2 and the safety of the operator when the construction machine rolls over can be more reliably achieved. When the support means is made of an elastic body such as a rubber, a spring, or an oil damper like the support body 5, it is necessary to increase the strength of the elastic body so that it can withstand a large load transmitted thereto. The manufacturing cost of the support means increases. However, when the support means is constituted by a support body 5 ', the support means can be manufactured with metal parts that are inexpensive and simple in structure. Can be produced.

  The example of FIG. 5 relating to the support means is a support as a support means by attaching rubber 9 to the inner peripheral portion of the insertion hole 7a of the inserted member 7 in the support body 5 ′ shown in FIGS. This is an example in which the body 5 ″ is configured. That is, the support 5 ″ is formed when the convex body 8a of the insertion member 8 is inserted into the insertion hole 7a of the member 7 to be inserted. An annular rubber 9 is fixed to the hole wall of the insertion hole 7a so that almost no gap is formed between the hole 8a and the hole 8a. Even when such a structure is adopted, when the convex body 8a is inserted into the insertion hole 7a, the rubber 9 can be deformed to displace the convex body 8a to some extent in the vertical and horizontal directions. It is comprised so that the relative displacement of the cab 2 with respect to the protection structure 3 for rooms may be permitted.

  The support 5 ″ in the example of FIG. 5 is such that the cab protection structure 3 is displaced in the horizontal direction with respect to the cab 2 due to vibrations generated in the swivel frame 1 when the self-propelled construction machine is running or working. Even so, it is possible to prevent an unpleasant collision sound from occurring due to collision between the hole wall of the insertion hole 7a of the inserted member 7 and the convex body 8a by acting on the rubber 9. Such rubber 9 Is fixed to the upper surface of the member 7 to be inserted and the lower surface of the mounting portion 8b of the member 8 to be inserted. If it is provided so as to eliminate direct contact with the insertion member 8, it is possible to prevent the occurrence of a collision sound when the cab protection structure 3 is displaced in the vertical direction. A construction machine with a working device such as a hydraulic excavator An example in which the present invention is embodied has been described, but the present invention relates to a crawler carrier (a self-propelled construction machine in which an upper revolving body having a dump-type cargo compartment is installed on a lower traveling body by a crawler). It can also be applied to construction machines such as

It is a perspective view of the principal part of the construction machine which concerns on the fundamental example which actualized this invention. It is a side view of the principal part of the construction machine of FIG. It is a perspective view which expands and shows another example of the support means in the construction machine which actualized this invention. FIG. 4 is a vertical sectional view of the supporting means of FIG. 3. It is a vertical sectional view which expands and shows the 2nd other example of the support means in the construction machine which materialized the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating frame 2 Driver's cab 2a Upper surface part 2b (Driving room 2) Front pillar 2c Center pillar 2d Rear pillar 2e Side surface part 2 (of driver's cab 2) Rear face 2g (Driving room 2) Front glass 2h Door 3 For driver's cab Protective structure 4a, 4b Post 5,5 ', 5 "Support 6 Vibration isolator 7 Inserted member 7a Insertion hole 8 Inserting member 8a Convex 9 Rubber

Claims (4)

In a construction machine including a swivel frame and a cab installed on the swivel frame, a cab protection structure for preventing the cab from being directly impacted when the construction machine rolls over is provided at the top of the cab. When the rear side of this cab protection structure is supported by a support structure member installed on the swivel frame, and the cab protection structure is impacted by the rollover of the construction machine A construction machine characterized in that support means capable of supporting the front side portion of the cab protection structure relative to the support structure member is provided between the top of the cab and the cab protection structure. . 2. The construction machine according to claim 1, wherein the support means is configured to allow relative displacement of the cab with respect to the cab protection structure. 3. The construction machine according to claim 2, wherein the support means is made of an elastic body such as rubber, a spring, or an oil damper. The construction machine according to any one of claims 1 to 3, wherein when the support means is provided between the top of the cab and the cab protection structure, the vertical direction for increasing the rigidity of the cab is provided. A construction machine characterized in that support means is provided above the upper end of the frame so as to overlap the upper end of the frame.

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