JP6924030B2 - Piston type concrete pump - Google Patents

Description

The present invention relates to a piston type concrete pump used when pumping ready-mixed concrete to a casting position.

In the piston type concrete pump, a pair of pump cylinders are driven by a pair of pump drive cylinders driven in opposite phases by hydraulic oil from a hydraulic pump so that ready-mixed concrete can be pumped alternately. Each of the pump drive cylinders is provided with a drive piston that is reciprocated and two hydraulic oil chambers for reciprocating the drive piston. One port for supplying hydraulic oil to these two hydraulic oil chambers and discharging hydraulic oil from the two hydraulic oil chambers is provided for each hydraulic oil chamber, and a hose is connected to each port. , The hydraulic oil is supplied to each hydraulic oil chamber and the hydraulic oil is discharged from the expansion hydraulic oil chamber through this hose (Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-185509 (see FIGS. 3 and 4)

By the way, there is a desire to increase the moving speed of the reciprocating drive piston. For that purpose, it is conceivable to thicken the hose connected to the port to increase the amount of hydraulic oil supplied to the hydraulic oil chamber. However, not only is there a limit to the thickness of the hose connected to the port, but thick hoses are expensive. As a result, the amount of hydraulic oil in the hydraulic oil chamber cannot be increased as desired, or it is difficult to carry out the hydraulic oil, so early improvement is desired.

Therefore, an object of the present invention is to provide a piston type concrete pump which is advantageous in terms of maintenance including hose replacement work while increasing the amount of hydraulic oil in the hydraulic oil chamber.

The piston-type concrete pump of the present invention is provided on the left and right sides with their axes substantially parallel to each other, and is driven by a pair of pump drive cylinders driven by hydraulic oil from a hydraulic pump in opposite phases, and the pair of pump drive cylinders. A pair of pump cylinders that are driven to alternately supply and discharge ready-mixed concrete are provided, and each of the pair of pump drive cylinders has a drive piston that is reciprocated and two for reciprocating the drive piston. Each of the two hydraulic oil chambers is provided with a set of ports for connecting a hose for supplying and discharging hydraulic oil, and the set of ports is of the pump drive cylinders of both pumps. It is characterized in that it is located above the reference line passing through the axis.

According to the above configuration, since each hydraulic oil chamber is provided with a set of ports for connecting hoses, hydraulic oil can be supplied or discharged from a set of ports in each hydraulic oil chamber. The amount of hydraulic oil supplied to each hydraulic oil chamber and the amount of hydraulic oil discharged from each hydraulic oil chamber can be dramatically increased. Therefore, the moving speed of the drive piston can be increased. In addition, since a set of ports is located above the reference line passing through the axes of both pump drive cylinders, some or all of the ports of the set of ports are directly beside or directly below the pump drive cylinders. Compared with the configuration provided in the above, all ports can be easily accessed from above the pump drive cylinder, which is advantageous in terms of maintenance including hose replacement work.

Further, the piston type concrete pump of the present invention has a set of ports provided in each of the two hydraulic oil chambers of the pump drive cylinder located on the left side of the pair of pump drive cylinders, the center of one port and the port. The angle between the first line connecting the axis of the pump drive cylinder in which is formed and the second line connecting the center of the other port and the axis of the pump drive cylinder in which the port is formed is two. The center line that divides evenly is displaced by a predetermined angle to the left from the vertical line passing through the axis of the pump drive cylinder, and the two hydraulic oil chambers of the pump drive cylinder located on the right side of the pair of pump drive cylinders. In each set of ports, the first line connecting the center of one port and the axis of the pump drive cylinder in which the port is formed, and the center of the other port and the pump in which the port is formed are formed. The center line that bisects the angle formed by the second line connecting the axis of the drive cylinder may be displaced to the right by a predetermined angle from the perpendicular line passing through the axis of the pump drive cylinder.

According to the above configuration, the center lines between the sets of ports provided in each of the two hydraulic oil chambers of the left and right pump drive cylinders are displaced outward in the left-right direction with respect to the vertical line, so that they are inward. Left and right pump drive compared to accessing a set of misaligned ports, that is, accessing each set of ports through the space between the insides of the left and right pump drive cylinders located side by side. Easy access to a set of ports through the open space on both the left and right sides of the cylinder, especially when replacing the hose connected to the set of ports located on each of the left and right sides, the hose replacement work is easy and quick. It can be done, which is further advantageous in terms of maintenance.

In the present invention, each of the two hydraulic oil chambers is provided with a set of hose connection ports for supplying and discharging hydraulic oil, and a set of ports passes through the axes of both pump drive cylinders. Since it is located above the reference line, it is possible to provide a piston-type concrete pump that is advantageous in terms of maintenance including hose replacement work while increasing the amount of hydraulic oil in the pump cylinder.

It is a schematic enlarged plan view of the main part of the piston type concrete pump of this invention. FIG. 5 is a cross-sectional view taken along the line CC in FIG. It is the whole plan view of the piston type concrete pump. It is an overall side view of the piston type concrete pump. FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is a cross-sectional view taken along the line BB in FIG. It is a top view of the pump drive cylinder which constitutes a piston type concrete pump. It is a vertical sectional side view of the pump drive cylinder. (A) is a view of FIG. 8 from the left side, and (b) is a sectional view taken along line DD in FIG. It is a top view of the state which the hose is connected to the port of a pair of pump drive cylinders. It is a side view of the state which the hose is connected to the port of a pair of pump drive cylinders. A relay block for sending pressure oil from a hydraulic pump to a pump drive cylinder, (a) is a plan view, (b) is a right side view, (c) is a front view, and (d) is a rear view. (E) is a left side view. It is a bypass pipe attached to the relay block shown in FIG. 12 to change the supply location to the pump drive cylinder, (a) is a perspective view seen from above, (b) is a plan view, and (c). Is a perspective view seen from below. It is a hydraulic circuit diagram of a piston type concrete pump in the case of sending ready-mixed concrete at high pressure. It is a hydraulic circuit diagram of a piston type concrete pump in the case of sending ready-mixed concrete at a low pressure.

Hereinafter, a piston-type concrete pump (hereinafter, simply referred to as a concrete pump) according to an embodiment of the present invention will be described. The concrete pump is a pump that is mounted on a concrete pump truck (not shown) and pumps ready-mixed concrete. Specifically, as shown in FIG. 1, the concrete pump 1 includes a concrete pump main body 2 and a valve device 3 arranged behind the concrete pump main body 2.

The concrete pump main body 2 is composed of a repulsive pump driven by a flood control, and includes a pump cylinder 21 on the left side and a pump cylinder 22 on the right side which are parallel to each other in the left-right direction. At the base ends (front ends) of the pair of left and right pump cylinders 21 and 22, a left pump drive cylinder 23 for driving the left pump cylinder 21 and a right pump drive cylinder 24 for driving the right pump cylinder 22 are provided. They are integrally connected in the axial direction via the center frame 25. Further, pump pistons 21a and 22a that are slidably fitted are arranged in the pair of pump cylinders 21 and 22, and are slidably fitted in the pair of pump drive cylinders 23 and 24. Drive pistons 23a and 24a are arranged. The pump piston 21a in the left pump cylinder 21 and the drive piston 23a in the left pump drive cylinder 23 are integrally connected by the left piston rod 26 that slidably penetrates the center frame 25, and the right side. The pump piston 22a in the pump cylinder 22 and the drive piston 24a in the drive cylinder 24 on the right side are integrally connected by a piston rod 27 on the right side that slidably penetrates the center frame 25. The drive pistons 23a and 24a have the second hydraulic oil chambers 23b and 24b on the piston rods 26 and 27 side and the first hydraulic oil chambers 23c on the pistons 23a and 24a side in the corresponding pump drive cylinders 23 and 24. It is divided into 24c and 24c. The tips (rear ends) of the pump cylinders 21 and 22 are opened as discharge ends. The discharge ends 21b and 22b of the pump cylinders 21 and 22 are communicated with each other on the front surface of the valve device 3.

The valve device 3 includes a valve casing 31, a bottom lid 32, an S valve 33 (that is, a swing valve pipe), an S valve driving means 34, and a discharge pipe 35. The valve casing 31 is formed in a frame shape by the front wall 31a, the rear wall 31b, and the left and right side walls 31c and 31c, and the lower portion is opened by the opening 31d. The bottom lid 32 opens and closes the opening 31d at the bottom of the valve casing 31 by a cylinder (see FIG. 4).

As shown in FIGS. 1 and 2, a curved tubular S-valve 33 is housed in the lower portion of the valve casing 31. The S valve 33 is integrally formed with the S valve 33 so as to be rotatable around the axis of the rotation support shaft 33a parallel to the axis of each pump cylinder 21 and 22, and the discharge ends of the pair of pump cylinders 21 and 22. The 21b and 22b and the suction port 33b can be alternately switched to a communication state.

An S-valve driving means 34 for switching and driving the S-valve 33 by rotating the rotary support shaft 33a in synchronization with the operation of both pump pistons 21a and 22a is connected to the rotary support shaft 33a. .. In the S valve driving means 34, the tip portions of the left single-acting valve drive cylinder 34a and the right single-acting valve drive cylinder 34b, which are configured in cooperation with each other, are integrally formed from the rotary support shaft 33a. It is connected via an extending connecting arm 34c, and the base ends of both valve drive cylinders 34a and 34b are rotatably connected to the concrete pump main body 2.

When the concrete pump is in operation, the pair of valve drive cylinders 34a and 34b puts the pair of left and right pump cylinders 21 and 22 in the ready-mixed concrete suction state into the valve casing 31 and in the ready-mixed concrete pumping state. The ready-mixed concrete is smoothly pumped by switching drive control of the S valve 33 so that a certain object is alternately connected to the suction port 33b. That is, the S valve 33 has a first switching position in which the suction port 33b is connected to the discharge end 21b of the pump cylinder 21 on the left side and a second switching position in which the suction port 33b is connected to the discharge end 22a of the pump cylinder 22 on the right side. It is possible to reciprocate (swing) between the two, and the first switching position is reached by the extension operation of the valve drive cylinder 34a on the left side, and the second switching position is reached by the extension operation of the valve drive cylinder 34b on the right side. It is switched and held.

The front end of the discharge pipe 35 is connected to the rear wall 31b of the valve casing 31 and is always in communication with the S valve 33, and the rear end thereof is connected to the boom pipe of the boom device of the concrete pump vehicle (not shown). Be connected.

The hopper H that accepts ready-mixed concrete is shown by the alternate long and short dash line in FIGS. 2 and 3. The hopper H is connected to the upper part of the valve casing 31.

As shown in FIG. 3, the pair of pump drive cylinders 23 and 24 are arranged close to each other so as to have a slight gap in the left-right direction in a state where the axes X1 and X2 are parallel (may be substantially parallel). The pump drive cylinders 23 and 24 are connected to the main bodies 23A and 24A having a substantially circular outer shape and the flanges 23F and 24F at one end of the main bodies 23A and 24A (the front end on the opposite side to the pump cylinder side). The first port forming portions 23B, 24B and the main body portions 23A, 24A, which have a slightly larger outer shape than the main body portions 23A and 24A and are formed with the two first ports 231a, 231b, 241a and 241b described later. It is connected to the flanges 23f and 24f at the other end (rear end on the pump cylinder side), has a larger outer shape than the first port forming portions 23B and 24B, and has two second ports 232a and 232b described later. The second port forming portions 23C and 24C on which 242a and 242b are formed are provided.

As shown in FIGS. 1, 3 and 4, the left and right pump drive cylinders 23 and 24 have a reciprocating drive pistons 23a and 24a and a first hydraulic oil chamber for reciprocating the drive pistons 23a and 24a. First ports 231a, 231b, 241a for connecting two hoses for supplying and discharging hydraulic oil to the 23c, 24c and the second hydraulic oil chambers 23b, 24b and the two first hydraulic oil chambers 23c, 24c. , 241b, and second ports 232a, 232b, 242a, 242b for connecting two hoses for supplying and discharging hydraulic oil to the two second hydraulic oil chambers 23b and 24b. The two second ports 232a, 232b or 242a, 242b provided in the second hydraulic oil chamber 23c or 24c have a second flat surface 23t formed at two locations in the circumferential direction of the second port forming portion 23C or 24C having a circular outer shape. It is formed to penetrate in the radial direction from the center of each of the 24 tons in the circumferential direction. Further, the two first ports 231a, 231b or 241a, 241b provided in the first hydraulic oil chamber 23c or 24c are first flat surfaces formed at two locations in the circumferential direction of the first port forming portion 23B or 24B having a circular outer shape. It is formed through the center of each of the 23T or 24T in the circumferential direction in the radial direction. Note that 231a, 231b, 232a, 232b, 241a, 241b, 242a, and 242b each correspond to a set of ports.

As shown in FIG. 5, the four ports 231a, 231b, 241a, 241b provided at the front ends of both pump drive cylinders 23 and 24 are the axial centers of the first port forming portions 23B and 24B of both pump drive cylinders 23 and 24. It is located above the reference line L passing through X1 and X2. Further, as shown in FIG. 6, the four ports 232a, 232b, 242a, 242b provided at the rear ends of both pump drive cylinders 23 and 24 are the second port forming portions 23C and 24C of both pump drive cylinders 23 and 24. It is located above the reference line L passing through the axes X1 and X2 in.

As described above, each hydraulic oil chamber 23c or 24c or 23b or 24b (see FIG. 1) is provided with ports 231a, 231b or 241a, 241b or 232a, 232b or 242a, 242b for connecting two hoses. The hydraulic oil is supplied to the first hydraulic oil chamber 23c on the left side at the same time from the two first ports 231a and 231b, or the hydraulic oil in the first hydraulic oil chamber 23c on the left side is simultaneously supplied from the two first ports 231a and 231b. Can be discharged. Further, the hydraulic oil is simultaneously supplied to the first hydraulic oil chamber 24c on the right side from the two first ports 241a and 241b, or from the two first ports 241a and 241b at the same time in the first hydraulic oil chamber 24c on the right side. The hydraulic oil can be discharged. Further, the hydraulic oil is supplied to the left second hydraulic oil chamber 23b from the two second ports 232a and 232b at the same time, or from the two second ports 232a and 232b at the same time in the left secondary hydraulic oil chamber 23b. The hydraulic oil can be discharged. Further, the hydraulic oil is supplied to the second hydraulic oil chamber 24b on the right side at the same time from the two second ports 242a and 242b, or the hydraulic oil is simultaneously supplied from the two second ports 242a and 242b in the second hydraulic oil chamber 24b on the right side. The hydraulic oil can be discharged. Therefore, the amount of hydraulic oil supplied to each hydraulic oil chamber 23c ... and the amount of hydraulic oil discharged into each hydraulic oil chamber 23c ... Can be dramatically increased. Therefore, the moving speed of the drive pistons 23a and 24a can be increased. Further, all eight ports 231a, 231b, 241a, 241b, 232a, 232b, 242a, 242b provided in both pump drive cylinders 23 and 24 pass through the axes X1 and X2 of both pump drive cylinders 23 and 24. Since it is located above L, all the ports 231a, 231b, are compared with the configuration in which some or all of the eight ports are provided directly beside or directly below the pump drive cylinders 23, 24. Access to 241a, 241b, 232a, 232b, 242a, and 242b can be easily performed from above the pump drive cylinders 23 and 24, which is advantageous in terms of maintenance including hose replacement work.

More specifically, as shown in FIGS. 5 and 6, the two hydraulic oil chambers 23c and 23b of the pump drive cylinder 23 located on the left side of the pair of pump drive cylinders 23 and 24 (see FIG. 1). In the two first ports 231a and 231b and the two second ports 232a and 232b provided respectively, the center of one port 231a or 232a and the axial center of the left pump drive cylinder 23 in which the port 231a or 232a is formed. The angle Ψ1 or Ψ2 formed by the first line S1 connecting X2 and the second line S2 connecting the center of the other port 231b or 232b and the axis X2 of the pump drive cylinder 23 on the left side (FIGS. 5 and 6). The center line C1 that bisects the left side (see) is at a predetermined angle θ1 or θ2 (22 in both FIGS. 5 and 6) from the vertical line Z passing through the axis X2 of the pump drive cylinder 23 on the left side to the left side (right side in the figure). The pump drive cylinder 23 on the left side is rotated clockwise in FIG. 5 so as to be displaced (5.5 degrees). In FIG. 6, since the angle of θ2 is the same as the angle from the second line S2 to C1, the second line S2 and the perpendicular line Z are the same line. Further, two first ports 241a and 241b and two second ports provided in each of the two hydraulic oil chambers 24c and 24b (see FIG. 1) of the pump drive cylinder 24 located on the right side of the pair of pump drive cylinders 23 and 24. In the two ports 242a and 242b, the center line C1 between the two first ports 241a and 241b or between the two second ports 242a and 242b is on the right side from the perpendicular line Z passing through the axis X1 of the pump drive cylinder 24 on the right side. The pump drive cylinder 24 on the right side is opposite to the pump drive cylinder 24 on the left side in FIG. 5 so as to be displaced by a predetermined angle (22.5 degrees in both FIGS. 5 and 6) to (the left side in the figure). It is arranged by rotating it counterclockwise.

In this way, the two ports 231a, 231b, 232a, 232b, 241a, 241b, 242a, 242b provided in the two hydraulic oil chambers 23c, 23b, 24c, 24b of the left and right pump drive cylinders 23 and 24, respectively. Since each of the center lines C1 between them is displaced outward in the left-right direction with respect to the vertical line Z, when accessing two ports displaced inward, that is, the left and right pumps installed on the left and right sides Compared to accessing each of the two ports through the space between the insides of the drive cylinders 23 and 24, the two ports 231a, 231b or 241a, through the spaces opened on both the left and right sides of the left and right pump drive cylinders 23 and 24, Hose 38, 36 or 37, 39 with easy access to 241b or 232a, 232b or 242a, 242b, especially connected to two ports 231a, 231b or 241a, 241b located on each of the left and right sides (see FIG. 10). When replacing the hoses 38, 36, 37, 39, the replacement work can be easily and quickly performed, which is further advantageous in terms of maintenance.

Explaining the four first ports 231a, 231b, 241a, 241b and the four second ports 232a, 232b, 242a, 242b, the diameters of the first ports 231a, 231b, 241a, 241b are the diameters of the second ports 232a, 232b. The first angles Ψ1, Ψ1 (see FIG. 5) between the centers of the first ports 231a, 231b, 241a, 241b, which are slightly larger than the diameters of the first ports 231a, 231b, 241a, 241b, are slightly larger than the diameters of the second ports 232a, 232b, 242a, 242b. It is set larger than the second angles Ψ2 and Ψ2 (see FIG. 6) between the centers of. Specifically, the angle between the centers of the first port 231a, 231b or 241a, 241b, the angle Ψ1 formed by the first line S1 and the second line S2 shown in FIG. 5 is 90 degrees, and the second port 232a, The angle between the centers of 232b or 242a, 242b, the angle Ψ2 formed by the first line S1 and the second line S2 shown in FIG. 6, is 45 degrees, which is half of 90 degrees in FIG.

As shown in FIGS. 10 and 11, eight hoses 36,37,38,39,45,46,47,48 are connected to the eight ports 231a, 231b, 241a, 241b, 232a, 232b, 242a, 242b. The other ends of the eight hoses 36, 37, 38, 39, 45, 46, 47, 48 are connected to the relay block 44. One end of four hoses 40, 41, 42, 43 for supplying or discharging pressure oil to the block 44 is connected, and the other end of the four hoses 40, 41, 42, 43 is two pump units 49. , 50 is connected.

The block 44 is formed in a substantially rectangular parallelepiped shape, and as shown in FIGS. 10 and 12 (a) to 12 (e), the block 44 has 12 ports 51 for connecting the 12 hoses 36 to 43, 45 to 48. ~ 62 is formed. Two hoses 36, one ends of which are connected to the two ports 51 and 52 formed at the front end of the block 44 to the first ports 231b and 241a inside the front ends of the left and right pump drive cylinders 23 and 24, respectively. , 37 are connected to each other. Further, the front side of the four ports 53, 54, 55, 56 formed on the left side surface of the block 44 and the front side of the four ports 57, 58, 59, 60 formed on the right side surface of the block 44. The other ends of the two hoses 38 and 39, one ends of which are connected to the first ports 231a and 241b on the outer side of the front ends of the left and right pump drive cylinders 23 and 24, are connected to the port 57, respectively. Further, of the four ports 53, 54, 55, 56 formed on the left side surface of the block 44, the second and third ports 54, 55 from the front side and the four ports 57, 58 formed on the right side surface of the block 44. , 59, 60, the second and third ports 58, 59 from the front side are connected to the other ends of the four hoses 40, 41, 42, 43 connected to the two pump units 49, 50, respectively. Will be done. Further, of the four ports 53, 54, 55, 56 formed on the left side surface of the block 44, the rear port 56 and the four ports 57, 58, 59, 60 formed on the right side surface of the block 44. The other ends of the two hoses 45 and 46, one ends of which are connected to the outer second ports 232a and 242b of the rear ends of the left and right pump drive cylinders 23 and 24, are connected to the rear port 60, respectively. NS. Further, two hoses having one ends connected to the two ports 61 and 62 formed on the rear surface of the block 44 to the second ports 232b and 242a inside the rear ends of the left and right pump drive cylinders 23 and 24, respectively. The other ends of 47 and 48 are connected, respectively.

Then, as shown in FIGS. 12A to 12E and FIG. 14, the port 51 on the right side of the front surface of the block 44 and the port 57 on the front side of the right side surface of the block 44 are formed on the upper surface of the block 44 on the front side. It communicates with port 67 on the right side. Further, the port 52 on the left side of the front surface of the block 44 and the port 53 on the front side of the left side surface of the block 44 communicate with the port 68 on the left side on the front side formed on the upper surface of the block 44. Further, the second and third ports 58 and 59 from the front side of the right side surface of the block 44 communicate with the right port 69 at the center in the front-rear direction formed on the upper surface of the block 44. Further, the second and third ports 54 and 55 from the front side of the left side surface of the block 44 communicate with the port 70 on the left side at the center in the front-rear direction formed on the upper surface of the block 44. Further, the port 56 on the rear side of the left side surface of the block 44 and the port 61 on the left side of the rear surface of the block 44 communicate with the port 71 on the left side in the front-rear direction formed on the upper surface of the block 44. Further, the port 60 on the rear side of the right side surface of the block 44 and the port 62 on the right side of the rear surface of the block 44 communicate with the port 72 on the right side in the front-rear direction formed on the upper surface of the block 44.

As shown in FIG. 14, two ports 67 and 69, 68 and 70, 71 and 72 of the six ports 67, 68, 69, 70, 71, 72 on the upper surface of the block 44 are connected, respectively. It is provided with three bypass pipes 73 having the same configuration for the purpose. As shown in FIGS. 13 (a) to 13 (c), each bypass pipe 73 includes a rectangular plate portion 73A and a raised portion 73B for forming an oil passage that is arched upward from the upper surface of the plate portion 73A. It has. The plate portion 73A has, for example, an inlet port 73C that receives hydraulic oil from one of the two ports 67 and 69, and an oil formed in an arch shape from the hydraulic oil that has entered the inlet port 73C. It includes an outlet port 73D for discharging through the road 73E to the other port 69 or 67. Further, the bypass pipe 73 is provided with a plurality of (8 in the figure) bolt insertion holes 73F, and a screw hole 44a (not shown) formed in the block 44 through the bolt insertion holes 73F (not shown). By screwing into 12 (a)), three bypass pipes 73 are attached to the block 44 (see FIG. 10). The oil passage 73E is formed so as to rise upward from the inlet port 73C and then extend in the horizontal direction, and extend downward from the end in the horizontal direction to guide the outlet port 73D.

FIG. 14 shows a hydraulic circuit diagram in which two pump units 49 and 50, a block 44, and left and right pump drive cylinders 23 and 24 are connected via a hose, and the hydraulic circuit diagram will be described. The two pump units 49, 50 have a variable capacity for sucking hydraulic oil in one of the pair of pump drive cylinders 23, 24 and supplying the hydraulic oil in the other pump drive cylinder 24 or 23 to the other pump drive cylinder 24 or 23. The reversible pumps 491 and 501 of the formula, the charge pumps 492 and 502 for replenishing the hydraulic oil so that the amount of hydraulic oil from the reversible pumps 491 and 501 becomes a predetermined amount, and the charge pumps 492 and 492 from the reversible pumps 491 and 501. It is provided with a pair of check valves 493, 493 and 503, 503 for blocking the inflow of hydraulic oil to the 502 side. These reversible pumps 491 and 501 and charge pumps 492 and 502 are driven by the rotation of the output shaft e of the engine E.

The excess hydraulic oil of the hydraulic oil sent from the charge pumps 492 and 502 is returned to the oil tank T via the return oil passages 74 and 74. The return oil passages 74 and 74 have a cooling device 75 for cooling the returned hydraulic oil, and when the hydraulic oil exceeds a predetermined pressure, the pressure is lowered to a predetermined pressure by returning the hydraulic oil to the oil tank T. It is equipped with a relief valve 76 for the purpose. The cooling device 75 is configured as an air-cooled type that cools the hydraulic oil by the wind from the fan 75A that is driven and rotated by the motor M.

Further, at ports 77 and 78 connected to the reversible pump 501 of one of the pump units 50, a part of hydraulic oil that continues to circulate in the closed oil passage between the reversible pump 501 and the pair of pump drive cylinders 23 and 24. A flushing valve 79 is provided as a control valve for replacing the hydraulic oil in the closed oil passage by letting the oil into the oil tank T.

The connection of the ports by the bypass pipe 73 is different between the hydraulic circuit diagram of FIG. 14 and the hydraulic circuit diagram of FIG. That is, in FIG. 14, hydraulic oil is extracted from the hydraulic oil chamber 24c on the front end side of one pump drive cylinder 24, and the extracted hydraulic oil is supplied to the hydraulic oil chamber 23c at the front end of the other pump drive cylinder 23. Bypass pipe 73 is connected to. Further, in FIG. 15, hydraulic oil is extracted from the hydraulic oil chamber 23b at the rear end of one pump drive cylinder 23, and the extracted hydraulic oil is supplied to the hydraulic oil chamber 24b at the rear end of the other pump drive cylinder 24. The bypass pipe 73 is connected so as to do so.

The hydraulic circuit of FIG. 14 will be described. The pressure receiving area of the hydraulic oil on the hydraulic oil chambers 23c and 24c at the front ends of the pump drive cylinders 23 and 24 shown in FIG. 14 is the hydraulic oil chambers 23b and 24b at the rear ends of the pump drive cylinders 23 and 24 shown in FIG. Since it is larger than the pressure receiving area of the hydraulic oil on the pump, FIG. 14 is a hydraulic circuit diagram in which the pair of pump drive cylinders 23 and 24 are driven at high pressure. First, in FIG. 14, when the reversible pumps 491 and 501 are driven so as to supply the hydraulic oil from the bottom to the top, the hydraulic oil in the hydraulic oil chamber 23c on the piston side of the left pump drive cylinder 23 becomes 2 of the block 44. After entering the ports 52 and 53 on the inlet side, the pumps are discharged from the two ports 54 and 55 on the outlet side via the bypass pipe 73. The discharged hydraulic oil is sucked through the lower ports 78 and 81 of the reversible pumps 491 and 501, and then discharged from the upper ports 77 and 80. The discharged hydraulic oil enters the two ports 58 and 59 on the inlet side of the block 44, and then is discharged from the two ports 51 and 57 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 24c at the front end via the two first ports 241a and 241b of the pump drive cylinder 24 on the right side. As a result, the hydraulic oil in the hydraulic oil chamber 24b at the rear end of the pump drive cylinder 24 on the right side is discharged from the two second ports 242a and 242b and enters the two ports 60 and 62 on the inlet side of the block 44. It is discharged from the two ports 56 and 61 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 23b at the rear end via the two second ports 232a and 232b of the pump drive cylinder 23 on the left side. As a result, the pump drive cylinder 23 on the left side operates in a shortened manner to suck in ready-mixed concrete, and the pump drive cylinder 24 on the right side operates to extend and discharges ready-mixed concrete to be pumped through a pipe (not shown). .. When the suction amount of the reversible pumps 491 and 501 decreases, the hydraulic oil from the charge pumps 492 and 502 is replenished.

Contrary to the above, when the reversible pumps 491 and 501 are driven to supply hydraulic oil from top to bottom, the hydraulic oil in the hydraulic oil chamber 24c at the front end of the pump drive cylinder 24 on the right side becomes two in the block 44. After entering the ports 51 and 57 on the inlet side, the oil is discharged from the two ports 58 and 59 on the outlet side via the bypass pipe 73. The discharged hydraulic oil is sucked through the upper ports 77 and 80 of the reversible pumps 491 and 501, and then discharged from the lower ports 78 and 81. The discharged hydraulic oil enters the two ports 54 and 55 on the inlet side of the block 44, and then is discharged from the two ports 52 and 53 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 23c at the front end portion via the two first ports 231a and 231b of the pump drive cylinder 23 on the left side. As a result, the hydraulic oil in the hydraulic oil chamber 23b at the rear end of the pump drive cylinder 23 on the left side is discharged from the two second ports 232a and 232b and enters the two ports 56 and 61 on the inlet side of the block 44. It is discharged from the two ports 60 and 62 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 24b at the rear end via the two second ports 242a and 242b of the pump drive cylinder 24 on the right side. As a result, the pump drive cylinder 23 on the left side expands to discharge ready-mixed concrete and is pumped through a pipe (not shown), and the pump drive cylinder 24 on the right side shortens to suck in ready-mixed concrete. When the suction amount of the reversible pumps 491 and 501 decreases, the hydraulic oil from the charge pumps 492 and 502 is replenished.

Next, the hydraulic circuit of FIG. 15 will be described. The pressure receiving area of the hydraulic oil on the hydraulic oil chambers 23b and 24b at the rear ends of the pump drive cylinders 23 and 24 shown in FIG. 15 is the hydraulic oil chambers 23c and 24c at the front ends of the pump drive cylinders 23 and 24 shown in FIG. Since it is smaller than the pressure receiving area of the hydraulic oil on the pump, FIG. 15 is a hydraulic circuit diagram in which the pair of pump drive cylinders 23 and 24 are driven at low pressure. In FIG. 15, the pump unit 49 and 50 sides are omitted in the hydraulic circuit diagram. First, when the reversible pumps 491 and 501 (see FIG. 14) are driven so as to supply the hydraulic oil from the bottom to the top, the hydraulic oil in the hydraulic oil chamber 23b on the piston rod side of the left pump drive cylinder 23 becomes the block 44. After entering the ports 56 and 61 on the two inlet sides of the above, the pumps are discharged from the two ports 54 and 55 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is sucked through the lower ports 78 and 81 of the reversible pumps 491 and 501 and then discharged from the upper ports 77 and 80 (see FIG. 14). The discharged hydraulic oil enters the two ports 58 and 59 on the inlet side of the block 44, and then is discharged from the two ports 60 and 62 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 24b at the rear end via the two second ports 242a and 242b of the pump drive cylinder 24 on the right side. As a result, the hydraulic oil in the hydraulic oil chamber 24c at the front end of the pump drive cylinder 24 on the right side is discharged from the two first ports 241a and 241b, enters the two ports 51 and 57 on the inlet side of the block 44, and then bypassed. It is discharged from two ports 52 and 53 on the two outlet sides via the pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 23c at the front end portion via the two first ports 231a and 231b of the pump drive cylinder 23 on the left side. As a result, the pump drive cylinder 23 on the left side expands to discharge ready-mixed concrete and is pumped through a pipe (not shown), and the pump drive cylinder 24 on the right side shortens to suck in ready-mixed concrete. When the suction amount of the reversible pumps 491 and 501 decreases, the hydraulic oil from the charge pumps 492 and 502 is replenished.

Contrary to the above, when the reversible pumps 491 and 501 (see FIG. 14) are driven so as to supply the hydraulic oil from top to bottom, the hydraulic oil in the hydraulic oil chamber 24b at the rear end of the pump drive cylinder 24 on the right side is driven. Is discharged from the two ports 58 and 59 on the two outlet sides via the bypass pipe 73 after entering the ports 60 and 62 on the two inlet sides of the block 44. The discharged hydraulic oil is sucked through the upper ports 77 and 80 of the reversible pumps 491 and 501 and then discharged from the lower ports 78 and 81 (see FIG. 14). The discharged hydraulic oil enters the two ports 54 and 55 on the inlet side of the block 44, and then is discharged from the two ports 56 and 61 on the two outlet sides via the bypass pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 23b at the rear end via the two second ports 232a and 232b of the pump drive cylinder 23 on the left side. As a result, the hydraulic oil in the hydraulic oil chamber 23c at the front end of the pump drive cylinder 23 on the left side is discharged from the two first ports 231a and 231b, enters the two ports 52 and 53 on the inlet side of the block 44, and then bypassed. It is discharged from two ports 51 and 57 on the two outlet sides via the pipe 73. The discharged hydraulic oil is supplied to the hydraulic oil chamber 24c at the front end via the two first ports 241a and 241b of the pump drive cylinder 24 on the right side. As a result, the pump drive cylinder 23 on the left side operates in a shortened manner to suck in ready-mixed concrete, and the pump drive cylinder 24 on the right side operates to extend and discharges ready-mixed concrete to be pumped through a pipe (not shown). .. When the suction amount of the reversible pumps 491 and 501 decreases, the hydraulic oil from the charge pumps 492 and 502 is replenished.

The present invention can be modified in various ways without departing from the spirit of the present invention. In addition, the specific configuration of each part is not limited to the above embodiment. For example, the concrete pump of the present invention is not limited to the vehicle-mounted type, and may be a stationary type (placed on the ground or floor) concrete pump.

In the above embodiment, the switching valve is not required by using the reversible pump, but a pump capable of inflowing or discharging hydraulic oil in only one direction may be used. In this case, the inflow direction of the hydraulic oil is changed by the switching valve.

Further, in the above embodiment, the relay block 44 is used, but the block 44 may be omitted and the reversible pumps 491 and 501 and the pump drive cylinders 23 and 24 may be directly connected.

Further, in the above embodiment, the cooling device 75 and the relief valve 76 are provided in the return oil passage, but they may be omitted.

Further, in the above embodiment, the left angle θ1 or θ2 and the right angle θ1 or θ2, which are displaced to the left or right from the perpendicular line Z, are both set to the same angle, but they may be set to different angles. Further, the pump drive cylinders 23 and 24 were rotated so that the left angle θ1 or θ2, which is displaced to the left or right from the perpendicular line Z, and the right angle θ1 or θ2 are symmetrical, but the left angle θ1 or θ2 and the right. The pump drive cylinders 23 and 24 may be rotated so that the angles θ1 and θ2 of the above are asymmetrical on the left and right sides.

1 ... Concrete pump, 2 ... Concrete pump body, 3 ... Valve device, 21,22 ... Left and right pump cylinders, 21a, 22a ... Left and right pump pistons, 21b, 22b ... Discharge ends, 23, 24 ... Pump drive cylinders, 23A , 24A ... Main body, 23B, 24B ... First port forming part, 23C, 24C ... Second port forming part, 23F, 24F ... Flange, 23T, 24T ... First flat surface, 23a, 24a ... Drive piston, 23b, 24b ... 2nd hydraulic oil chamber, 23c, 24c ... 1st hydraulic oil chamber, 23f, 24f ... Flange, 23t, 24t ... 2nd flat surface, 25 ... Center frame, 26, 27 ... Left and right piston rods, 31 ... Valve Casing, 31a ... front wall, 31b ... rear wall, 31c, 31c ... left and right side walls, 31d ... opening, 32 ... bottom lid, 32S ... cylinder, 33 ... S valve, 33a ... rotating support shaft, 33b ... suction port, 34 ... S valve drive means, 34a, 34b ... left and right valve drive cylinders, 34c ... connecting arm, 35 ... discharge pipe, 36-43 ... hose, 45-48 ... hose, 44 ... block, 44a ... screw hole, 49, 50 ... Pump unit 51-62 ... Port, 67-72 ... Port, 73 ... Bypass pipe, 73A ... Plate part, 73B ... Raised part, 73C ... Inlet port, 73D ... Outlet port, 73E ... Oil passage, 73F ... Bolt Insertion hole, 74 ... Return oil passage, 75 ... Cooling device, 75A ... Fan, 76 ... Relief valve, 77, 78, 80, 81 ... Port, 79 ... Flushing valve, 231a, 231b, 241a, 241b ... First port, 232a, 232b, 242a, 242b ... 2nd port, 491,501 ... reversible pump, 492,502 ... charge pump, 493 ... check valve, C1 ... center line, E ... engine, e ... output shaft, H ... hopper, L ... reference line, M ... motor, S1 ... first line, S2 ... second line, T ... oil tank, X1, X2 ... axis, Z ... vertical line, θ1 ... angle, θ2 ... angle, Ψ1 ... first angle , Ψ2 ... 2nd angle

Claims (2)

A pair of pump drive cylinders that are installed on the left and right sides with their axes substantially parallel and are driven in opposite phases by hydraulic oil from a hydraulic pump, and a pair of pump drive cylinders that are driven by the pair of pump drive cylinders to alternately supply ready-mixed concrete. With a pair of pump cylinders to discharge,
Each of the pair of pump drive cylinders has a drive piston that is reciprocated, two hydraulic oil chambers for reciprocating the drive piston, and one of the two hydraulic oil chambers. First port for connecting two hoses for supplying hydraulic oil or discharging hydraulic oil in one hydraulic oil chamber and discharging hydraulic oil in the other hydraulic oil chamber or discharging hydraulic oil into the other hydraulic oil chamber Equipped with a second port for connecting two hoses for supplying,
The hydraulic oil is simultaneously supplied from the two first ports to the one hydraulic oil chamber, and the hydraulic oil in the other hydraulic oil chamber is simultaneously discharged from the two second ports, or the two second ports are simultaneously discharged. The hydraulic oil is simultaneously supplied from the two ports to the other hydraulic oil chamber, and the hydraulic oil in the one hydraulic oil chamber is discharged from the two first ports.
A piston-type concrete pump characterized in that the four ports are located above a reference line passing through an axial center of the pump drive cylinder including the four ports. In the two ports provided in each of the two hydraulic oil chambers of the pump drive cylinder located on the left side of the pair of pump drive cylinders, the center of one port and the axis of the pump drive cylinder in which the port is formed are formed. The center line that bisects the angle formed by the first line connecting the two and the second line connecting the center of the other port and the axis of the pump drive cylinder in which the port is formed is the pump drive cylinder. One of the two ports provided in each of the two hydraulic oil chambers of the pump drive cylinder located on the right side of the pair of pump drive cylinders, which is displaced to the left by a predetermined angle from the perpendicular line passing through the axis of the pump drive cylinder. The first line connecting the center of the port and the axis of the pump drive cylinder in which the port is formed, and the second line connecting the center of the other port and the axis of the pump drive cylinder in which the port is formed. The piston-type concrete pump according to claim 1, wherein the center line that divides the angle formed by the pump into two equal parts is displaced to the right by a predetermined angle from the vertical line passing through the axis of the pump drive cylinder.

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