JP5026308B2 - Construction machinery - Google Patents

Description

  The present invention relates to a construction machine such as a ground improvement machine or a pile driving machine, and more specifically, a work apparatus such as a screw drive apparatus or an auger drive apparatus is provided along a leader using two chains driven by a pair of hydraulic motors. It is related with the construction machine provided with the working device raising / lowering means to raise / lower.

In construction machines such as ground improvement machines and pile driving machines, a driven sprocket is provided on the upper part of the leader, and a driving sprocket driven by a hydraulic motor is provided on the lower part. Chain type lifting means is known in which both ends of a chain are connected to a work device such as a screw drive device or an auger drive device, and the chain is driven by a hydraulic motor to raise and lower the work device along a leader (for example, , See Patent Document 1). In addition, as a device for measuring the raising / lowering position of the working device, a rotary encoder that detects the number of rotations of the sprocket is generally used (for example, see Patent Document 2), and usually the hydraulic motor. The output shaft and the detection shaft of the rotary encoder are connected. Furthermore, a pile driving machine is also proposed in which two sets of working device lifting means such as a hydraulic motor and a chain are provided to increase the lifting force (moving force) of the working device. (For example, refer to Patent Document 3).
JP-A-8-269964 JP-A-8-74251 JP 2000-282464 A

  In the case of providing two sets of working device lifting means such as a hydraulic motor and a chain in order to increase the lifting force (moving force) of the working device, in the pile driving machine described in Patent Document 3, the guide frame is formed in a gate shape. In addition, the hydraulic motors are arranged at the lower part of the left and right vertical frames, and the sprockets are fixed to both ends of the sprocket shaft rotatably provided on the upper horizontal frame. Although it can be easily assembled, a gate-shaped guide frame is significantly more expensive than a normal reader.

  On the other hand, when two hydraulic motors are provided in one reader, considering the stability and maintainability during work, the two hydraulic motors are placed under the leader with the output shafts facing each other. It is preferable to arrange. However, if two hydraulic motors are arranged with the output shafts opposed to each other in this way, it becomes difficult to connect the output shaft of the hydraulic motor and the detection shaft of the rotary encoder. The rotational speed of the driven sprocket is detected by a rotary encoder.

  When the rotational speed of the driven sprocket is detected by the rotary encoder, it is conceivable to connect the detection shaft of the rotary encoder to the sprocket shaft that rotates integrally with the driven sprocket, but as described in Patent Document 3, If two driven sprockets are fixed to the sprocket shaft and formed to rotate at the same time, when the two chains become uneven in length, an excessive load will be applied to the shorter chain and the chain will It may cut off. For this reason, the driven sprockets must be provided on different sprocket shafts so that both sprockets can rotate independently. Furthermore, although the detection shaft of the rotary encoder must be connected to the sprocket shaft, it is difficult to provide two sprocket shafts and a plurality of bearings for supporting them in a limited space above the reader. It becomes necessary to change the shape and structure, or the combination of the reader and the working device becomes unbalanced, which causes an increase in cost.

  Therefore, according to the present invention, two driven sprockets can be independently rotated in a limited space of the reader, and a rotary encoder for detecting the number of rotations of one driven sprocket can be collectively arranged. The purpose is to provide construction machinery.

  In order to achieve the above object, the present invention provides a construction machine including a work device provided so as to be able to be lifted and lowered along a leader of a work machine, and a work device lifting means for lifting the work device through a chain. The working device lifting / lowering means is rotatable to the other end of the reader, a pair of hydraulic motors having an output shaft opposed to one end of the reader, a pair of drive-side sprockets respectively coupled to the output shafts of the hydraulic motors A pair of sprocket shafts, a pair of driven sprockets provided on the sprocket shaft, and a pair of chains that are spanned between the driving sprockets and the driven sprockets and connected to the working device And a rotary encoder that detects the number of rotations of one of the sprockets or the sprocket shaft, and the pair of driven sides In the procket, one driven sprocket is fixed to the sprocket shaft, and the other driven sprocket is rotatably provided to the sprocket shaft. The one driven sprocket is a key Alternatively, the sprocket shaft is preferably fixed to the sprocket shaft, and the other driven sprocket is preferably attached to the sprocket shaft via a bearing or a bush.

  According to the construction machine of the present invention, the two pairs of driven sprockets are rotatably provided independently, so even when the lengths of the pair of chains are not uniform, the load applied to each chain is evenly distributed. Can be. Further, since one driven sprocket rotates integrally with the sprocket shaft, the sprocket shaft and the detection shaft of the rotary encoder are connected to reliably measure the rotational speed of the driven sprocket, that is, the lift position of the work device. be able to. Further, since the sprocket shaft can be rotatably supported by two bearings, it can be easily disposed in a limited space above the leader.

  FIGS. 1 to 5 show an embodiment in which the present invention is applied to a ground improvement machine as a construction machine. FIG. 1 is a front view of a main part of the ground improvement machine, FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, FIG. 4 is a side view of the main part of the ground improvement machine, and FIG. 5 is a side view of the ground improvement machine.

  The ground improvement machine 1 has a leader 4 mounted on a front bracket 3 provided at the front part of a work machine 2 so that the leader 4 can be raised and lowered, and the leader 4 has a screw drive device that is a working device that moves up and down along the leader 4. 5 and working device lifting / lowering means 6 for lifting and lowering the screw driving device 5 are provided. Further, a screw guide 7 that holds the lower part of a screw shaft 5 a attached to the screw driving device 5 is provided at the lower part of the leader 4, and a top sheave 8 is provided at the upper part of the leader 4.

  The working device lifting / lowering means 6 includes a pair of speed reducer built-in hydraulic motors 9 and 9 that are opposed to each other so that output shafts from the speed reducer are positioned in a straight line on both side surfaces of the lower portion of the reader 4. A pair of drive-side sprockets 10 and 10 respectively coupled to the output shaft, a pair of driven-side sprockets 11a and 11b disposed on the top of the reader 4, each drive-side sprocket 10 and 10 and each driven-side sprocket 11a and 11b. And a pair of chains 12 and 12 having both ends connected to the screw drive device 5.

  The drive-side sprockets 10 and 10 are provided so as to rotate integrally with the respective output shafts, and an annular member 13 that prevents the drive-side sprockets 10 and 10 from coming off between the drive-side sprockets 10 and 10. Is sandwiched in a rotatable state. Since the drive-side sprockets 10 and 10 can rotate independently, even if the lengths of the chains 12 and 12 become uneven, the driving force is reliably transmitted to both the chains 12 and 12. can do.

  The driven-side sprockets 11a and 11b are connected to the driving-side sprocket 10 and the sprocket shaft 16 that are rotatably supported by a pair of bearings 14 and 14 provided on the top of the reader 4 via the bearings 15 and 15, respectively. 10 and corresponding positions.

  One driven sprocket 11a shown on the right side in FIG. 2 is attached to the large-diameter portion 16a of the sprocket shaft 16, and provided on the outer peripheral surface of the large-diameter portion 16a and the inner peripheral surface of the driven-side sprocket 11a. By inserting the key 17 into the key grooves 16b and 11c or by serration-coupling them, the sprocket shaft 16 is formed to rotate integrally. The other driven sprocket 11b shown on the left side in FIG. 2 has a bearing 18 interposed between the inner peripheral surface of the driven sprocket 11b and the outer peripheral surface of the sprocket shaft 16, and can rotate with respect to the sprocket shaft 16. Is attached. Further, collars 19a, 19b, 19c for regulating the axial position of the driven sprockets 11a, 11b are provided on the outer periphery of the sprocket shaft 16, and a lubricant such as grease is applied to the bearings 15, 15, 18 inside. An injection path 16c for injecting is provided.

  Further, a rotary encoder 21 for detecting the rotation speed of the sprocket shaft 16, that is, the rotation speed of the driven sprocket 11a, is provided on the outer surface of the bearing 14 on the driven sprocket 11a side through a cylindrical bracket 20. The detection shaft 21 a of the rotary encoder 21 is connected via a coupling 22 to a connecting shaft 16 d that protrudes in the axial direction from one end of the sprocket shaft 16.

  In this manner, one driven sprocket 11a is fixed to the sprocket shaft 16 so that the driven sprocket 11a and the sprocket shaft 16 rotate integrally, and the other driven sprocket 11b is connected via the bearing 18. The sprocket shaft 16 is formed so as to be rotatable, and the rotary encoder 21 is connected to one end of the sprocket shaft 16 so that the sprocket shaft 16 can be supported by two bearings 14 and 14. The driven sprockets 11a and 11b and the rotary encoder 21 can be arranged compactly in a limited space. Further, even when the lengths of the two chains 12 and 12 are not uniform, the driven sprockets 11a and 11b can rotate independently, so that the driven sprockets 11a can be driven from the hydraulic motors 9 and 9, respectively. , 11b, the tensile force and load of both the chains 12, 12 reaching the connecting portion with the screw drive device 5 can be made uniform.

  For example, when the screw drive device 5 is raised, the length of the chain 12 stretched over the other driven sprocket 11b is longer than the length of the chain 12 stretched over the one driven sprocket 11a. In this case, when hydraulic oil is supplied from the hydraulic device and the hydraulic motors 9 and 9 are started at the same time, the hydraulic motors 9 and 9 are independently rotatable. The chains 12 and 12 between the drive side sprockets 10 and 10 and the driven side sprockets 11a and 11b are stretched immediately after starting.

  Further, in each of the chains 12 and 12 between the driven sprockets 11a and 11b and the screw drive device 5, the length of the chain 12 stretched over the driven sprocket 11b is increased as described above. However, since the driven sprocket 11b rotates separately from the driven sprocket 11a, the chain 12 from the driven sprocket 11b to the screw drive device 5 is also stretched immediately after starting. Accordingly, both the chains 12 and 12 from the drive side sprockets 10 and 10 of the hydraulic motors 9 and 9 to the screw drive device 5 through the drive side sprockets 10 and 10 are both stretched, and both chains The tensile force and load of 12, 12 are equalized.

  On the other hand, when the driven side sprockets 11a and 11b are fixed to the sprocket shaft 16 and formed so as to rotate integrally, the hydraulic motors 9 and 9 rotate independently. The chains 12 and 12 between the driven side sprockets 11a and 11b are in a state of being stretched immediately after the start in the same manner as described above. However, between the driven side sprockets 11a and 11b and the screw driving device 5, the driven side sprockets 11a and 11b Since 11b rotates simultaneously, the slack of the long chain 12 cannot be eliminated.

  Therefore, between the driven sprockets 11a and 11b and the screw drive device 5, after one chain 12 having a short length is in a stretched state, only the one chain 12 in the stretched state is used for the screw drive device 5. Will be raised. For this reason, no load is applied to the other chain 12 having a longer length, and a load is applied only to the one chain 12 having a shorter length, and an excessive load acts on the one chain 12 to be cut. There is a fear.

  Then, as shown in the present embodiment, one driven-side sprocket 11a and the sprocket shaft 16 are formed so as to rotate integrally, and the rotary encoder 21 is connected to the sprocket shaft 16 so that the rotary encoder 21 The number of rotations of the driven sprocket 11a can be detected, and the elevation position of the screw drive device 5 can be measured from the amount of movement of the chain 12 and input to the construction management device. Further, since the rotary encoder 21 can be connected to the sprocket shaft 16 in the same way as the connection to the output shaft of a conventional hydraulic motor, the connecting parts can be shared and the assembly is easy. Therefore, there is no possibility that the reliability of the measurement state is lowered.

  Further, by forming the driven side of the working device lifting / lowering means 6 as described above, the two hydraulic motors 9 can be compactly arranged in the lower portion of the leader 4. Therefore, it is possible to use a general-purpose inexpensive hydraulic motor without using a large and expensive hydraulic motor. Further, since the two hydraulic motors 9 are arranged at the lower part of the leader 4, the center of gravity can be lowered and the stability can be improved as compared with the case where the hydraulic motor is arranged at the upper part of the leader 4, and the hydraulic piping is provided. There is no need to lengthen it.

  In this embodiment, the sprocket shaft 16 and the detection shaft 21a of the rotary encoder 21 are directly connected by the coupling 22. However, gears that mesh with each other are provided on the sprocket shaft 16 and the detection shaft 21a. The sprocket shaft 16 and the detection shaft 21a are connected via the sprocket shaft 16 and the sprocket shaft 16a are connected to the detection shaft 21a via the chain, and the sprocket shaft 16 and the detection shaft 21a are detected via the sprocket and the chain. The shaft 21a can also be connected. Further, the sprocket shaft side gear and sprocket can be provided integrally with the driven sprocket.

  Furthermore, the present invention is suitable for a ground improvement machine having a smaller rotational reaction force received from the working device than a pile driving machine and having a narrow leader width, but is not limited to a ground improvement machine, such as a pile driving machine and an excavator. It can be applied to various construction machines. In addition, the other driven sprocket that is rotatably attached to the sprocket shaft only needs to be rotated by an amount corresponding to the adjustment of the chain length. Therefore, a bush, not a bearing, may be interposed. Further, depending on conditions such as the length of the leader, the hydraulic motor and the driving side sprocket can be provided at the upper part of the leader, and the driven side sprocket can be provided at the lower part of the leader.

It is a principal part front view of the ground improvement machine which shows the example of 1 form of this invention. It is a principal part sectional view of the leader upper part of a ground improvement machine similarly. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a principal part side view of a ground improvement machine similarly. It is a side view of the ground improvement machine.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ground improvement machine, 2 ... Working machine, 3 ... Front bracket, 4 ... Leader, 5 ... Screw drive device, 5a ... Screw shaft, 6 ... Working device raising / lowering means, 7 ... Screw guide, 8 ... Top sheave, 9 ... Hydraulic motor, 11a, 11b ... driven sprocket, 11c ... key groove, 12 ... chain, 13 ... annular member, 14 ... bearing, 15, 18 ... bearing, 16 ... sprocket shaft, 16a ... large diameter part, 16b ... key groove 16c: injection path, 16d: connecting shaft, 17: key, 19a, 19b, 19c ... collar, 20 ... bracket, 21 ... rotary encoder, 21a ... detection shaft, 22 ... coupling

Claims (2)

In a construction machine including a working device provided so as to be able to be lifted and lowered along a leader of the working machine, and a working device lifting / lowering means for lifting and lowering the working device via a chain, the working device lifting / lowering means is one end of the leader. A pair of hydraulic motors having output shafts opposed to each other, a pair of drive-side sprockets coupled to each output shaft of each hydraulic motor, a sprocket shaft rotatably provided at the other end of the reader, and the sprocket shaft A pair of driven sprockets, a pair of chains spanned between the driving sprockets and the driven sprockets and connected to the working device, and one of the sprockets or the sprocket A rotary encoder that detects the rotational speed of the shaft, and the pair of driven sprockets includes one driven sprocket. Tsu: it is fixed on the sprocket shaft, the construction machine and the other driven sprocket, characterized in that is provided rotatably relative to the sprocket axis. 2. The one driven sprocket is fixed to the sprocket shaft by a key or a spline, and the other driven sprocket is attached to the sprocket shaft via a bearing or a bush. Construction machinery.

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