JP2021038707A - Cylinder block, liquid pressure device, construction machine, and manufacturing method of cylinder block - Google Patents

Abstract

To smoothen flow of a working oil between a connection port of a cylinder block and a cylinder chamber.SOLUTION: A cylinder block 20 includes: a cylinder wall surface part CW and a cylinder bottom surface part CB which form a cylinder chamber 21 extending in one direction DX and opening at one side in the one direction; a port wall surface part PW opening at the other side in the one direction and forming a connection port CP leading to the cylinder chamber; and inclined surface parts IS inclined relative to the one direction. Each inclined surface part IS connects with at least a part of a port wall surface, which is located offset from the cylinder chamber in a direction orthogonal to the one direction, and a cylinder wall surface.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for manufacturing a cylinder block, a hydraulic device, a construction machine, and a cylinder block for a hydraulic device.

For example, as disclosed in Patent Document 1, a hydraulic hydraulic device having a rotatable cylinder block and a piston arranged in a cylinder chamber of the cylinder block, typically a hydraulic device, is known. In this hydraulic device, the piston moves back and forth with the rotation of the cylinder block, and the volume of the cylinder chamber changes. The cylinder block is provided with a connection port leading to each cylinder chamber. A valve plate having a plurality of ports is arranged adjacent to the cylinder block. Each cylinder chamber is connected to the port of the valve plate via the connection port as the cylinder block rotates. The hydraulic fluid flows into or out of each cylinder chamber through the connection port and the valve plate port.

Japanese Unexamined Patent Publication No. 11-22654

By the way, when a step is formed between the connection port and the cylinder chamber, the flow of the hydraulic fluid (for example, hydraulic oil) between the connection port and the cylinder chamber is disturbed. If the hydraulic fluid cannot flow smoothly between the connection port and the cylinder chamber in this way, various problems may occur. For example, when a hydraulic device is used as a pump, cavitation occurs in the cylinder chamber on the low pressure side. Further, when the hydraulic device is used as a motor, a pressure loss occurs and the output decreases.

The present invention has been made in consideration of the above points, and an object of the present invention is to facilitate the flow of hydraulic fluid between the connection port of the cylinder block and the cylinder chamber.

The first cylinder block according to the present invention is
A cylinder wall surface portion formed along one direction and forming a cylinder chamber opened on one side in the one direction.
A cylinder end face portion formed on the other side of the cylinder wall surface portion in the one direction and having an opening at least in a part thereof.
A port wall surface that connects to the opening and forms a connection port that is located offset from the cylinder chamber in a direction orthogonal to the one direction.
A plurality of cylinder portions including at least a part of the port wall surface portion and at least a part of the cylinder wall surface portion and having an inclined surface portion inclined with respect to one direction are arranged in the circumferential direction about the rotation axis. ..

The second cylinder block according to the present invention is
A cylinder wall surface portion provided at intervals in the circumferential direction centered on an axis along one direction and each forming a plurality of cylinder chambers opened on one side in the one direction.
A cylinder end face connected to the cylinder wall surface from the other side in one direction,
A port wall surface that forms a connection port leading to the cylinder chamber,
It is provided with an inclined surface portion that connects at least a part of the port wall surface portion and at least a part of the cylinder wall surface portion and is inclined with respect to the one direction.

The third cylinder block according to the present invention is
A plurality of cylinder wall surfaces provided apart from each other in the circumferential direction centered on an axis parallel to one direction and each forming a plurality of cylinder chambers opened on one side in the one direction.
A plurality of cylinder end face portions connected to each cylinder wall surface portion from the other side in one direction to form each cylinder chamber together with the cylinder wall surface portion.
A plurality of port wall surfaces provided corresponding to each cylinder chamber and forming a connection port leading to the cylinder chamber from the other side in the one direction.
A plurality of inclined surface portions that connect the cylinder wall surface portion of each cylinder chamber and the port wall surface portion of the connection port corresponding to the cylinder chamber and are inclined with respect to the one direction are provided.

The fourth cylinder block according to the present invention is
A plurality of cylinder wall surfaces provided apart from each other in the circumferential direction centered on an axis parallel to one direction and each forming a plurality of cylinder chambers opened on one side in the one direction.
A plurality of cylinder end face portions connected to each cylinder wall surface portion from the other side in one direction to form each cylinder chamber together with the cylinder wall surface portion.
A plurality of port wall surfaces forming connection ports leading to the cylinder chamber from the other side in the one direction, and
A plurality of inclined surface portions that connect the cylinder wall surface portion and the port wall surface portion and are inclined with respect to the one direction are provided.

In the first to fourth cylinder blocks according to the present invention, the angle formed by the inclined surface portion with respect to the surface orthogonal to the one direction is larger than the angle formed by the cylinder bottom surface portion with respect to the surface orthogonal to the one direction. It may be made larger.

In the first to fourth cylinder blocks according to the present invention, the cylinder wall surface portion and the port wall surface portion may extend in the one direction.

In the first to fourth cylinder blocks according to the present invention,
The bottom surface of the cylinder faces the one side in the one direction.
The inclined surface portion may face the other side in the one direction.

In the first to fourth cylinder blocks according to the present invention, at least a part of the inclined surface portion may have a shape forming a part of a side surface portion of the cone.

In the first to fourth cylinder blocks according to the present invention, the connection port may have a shape protruding from the cylinder chamber in the circumferential direction of the cylinder block.

In the first to fourth cylinder blocks according to the present invention,
In the observation from the other side in one direction, the connection port extends linearly and is located at the end offset from the cylinder chamber.
The inclined surface portion may be provided at a position that becomes the end portion of the connection port.

In the first to fourth cylinder blocks according to the present invention, the inclined surface portion may form an angle of 30 ° or more and 70 ° or less with respect to the one direction.

In the first to fourth cylinder blocks according to the present invention, the roughness of the port wall surface portion may be smaller than the roughness of the inclined surface portion.

In the first to fourth cylinder blocks according to the present invention, a plurality of the inclined surface portions may be provided apart from each other.

In the first to fourth cylinder blocks according to the present invention,
In the observation from the other side in the one direction, a part of the port wall surface portion provided between the plurality of inclined surface portions and located offset from the cylinder chamber in the direction orthogonal to the one direction, and the cylinder wall surface portion. Equipped with a bottom part of the port to connect
The angle formed by the inclined surface portion with respect to the surface orthogonal to the one direction may be larger than the angle formed by the bottom surface portion of the port with respect to the surface orthogonal to the one direction.

In the first to fourth cylinder blocks according to the present invention, the port wall surface portion may face the other side in the one direction.

In the first to fourth cylinder blocks according to the present invention, the inclined surface portion may extend linearly when observed from the other side in the one direction.

In the first to fourth cylinder blocks according to the present invention, the inclined surface portions extending linearly when observed from the other side in the one direction have a shape forming a part of the side surface portion of the cone at both ends thereof. You may.

The fifth cylinder block according to the present invention is
A cylinder wall surface portion provided at intervals in the circumferential direction centered on an axis along one direction and each forming a plurality of cylinder chambers opened on one side in the one direction.
A cylinder end face connected to the cylinder wall surface from the other side in one direction,
A port wall surface that forms a connection port leading to the cylinder chamber,
An inclined surface portion that connects at least a part of the port wall surface portion and at least a part of the cylinder wall surface portion and is inclined with respect to the one direction is provided.
At least a part of the inclined surface portion has a shape forming a part of the side surface portion of the cone.
In the circumferential direction, the connection port has a shape protruding from the cylinder chamber.
The inclined surface portion has an angle of 30 ° or more and 70 ° or less with respect to the one direction.

The hydraulic device according to the present invention includes any of the first to fifth cylinder blocks according to the present invention described above.

The construction machine according to the present invention includes any of the hydraulic devices according to the present invention described above.

The method for manufacturing the first cylinder block according to the present invention is as follows.
A step of advancing a processing tool having a tapered tip portion to one side in one direction to form a hole in the base material including an inclined surface portion inclined with respect to the one direction and opening to the other side in the one direction.
The step includes a step of cutting the base material from the one side in the one direction to form a cylinder chamber to be connected to the hole in the inclined surface portion.
In the method for manufacturing a cylinder block for the first hydraulic device according to the present invention, either the cylinder chamber or the hole may be formed first.

The method for manufacturing the second cylinder block according to the present invention is
The process of manufacturing the base material including the cylinder chamber opened on one side in one direction,
A step of advancing a processing tool having a tapered tip portion from the other side in the one direction to the one side, and forming a hole including an inclined surface portion inclined in the one direction and connected to the cylinder chamber in the base material. And.

In the step of forming the holes in the method for manufacturing the first and second cylinder blocks according to the present invention, a plurality of holes separated from each other may be formed.

The method for manufacturing the first and second cylinder blocks according to the present invention is such that the other processing tool is moved in a direction intersecting the one direction so that the inclined surface portion is left at least partially, so that the original material can be manufactured. A step of cutting between the plurality of holes may be provided.

In the method for manufacturing the first and second cylinder blocks according to the present invention, the surface roughness of the surface portion formed by using the other processing tool is larger than the roughness of the inclined surface portion formed by using the processing tool. It may be made smaller.

The method for manufacturing the first and second cylinder blocks according to the present invention may include a step of moving the processing tool in a direction intersecting the one direction to widen the hole.

In the method for manufacturing the first and second cylinder blocks according to the present invention, the processing tool is moved in the direction intersecting the one direction so that the inclined surface portion is left at least partially as it is, and the hole is roughened. A step of reducing the roughness may be provided.

According to the present invention, the flow of the hydraulic fluid between the connection port of the cylinder block and the cylinder chamber can be smoothed.

FIG. 1 is a diagram for explaining an embodiment of the present invention, and is a side view showing an example of a construction machine to which a hydraulic pressure device can be applied. FIG. 2 is a vertical cross-sectional view showing an example of a hydraulic device that can be applied to the construction machine of FIG. FIG. 3 is a plan view showing a cylinder block included in the hydraulic device of FIG. FIG. 4A is a plan view showing an example of a valve plate included in the hydraulic device of FIG. FIG. 4B is a plan view showing another example of the valve plate included in the hydraulic device of FIG. FIG. 5 is a cross-sectional view taken along the line VV of FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 7 is a cross-sectional view for explaining an example of a method of forming a connection port and a cylinder chamber of the cylinder block of FIG. FIG. 8 is a cross-sectional view for explaining an example of a method of forming a connection port and a cylinder chamber of the cylinder block of FIG. FIG. 9 is a cross-sectional view for explaining an example of a method of forming a connection port and a cylinder chamber of the cylinder block of FIG. FIG. 10 is a cross-sectional view for explaining another example of the method of forming the connection port and the cylinder chamber of the cylinder block of FIG. FIG. 11 is a cross-sectional view for explaining still another example of the method of forming the connection port and the cylinder chamber of the cylinder block of FIG. FIG. 12 is a diagram corresponding to FIG. 5 and is a diagram showing a modified example of the cylinder block. FIG. 13 is a diagram showing a reference example of a cylinder block in the same cross section as in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that the elements shown in each drawing may include elements whose size, scale, etc. are shown differently from those actually shown in order to facilitate understanding. Further, in the following embodiment, an example in which the hydraulic pressure device according to the present embodiment is applied to the hydraulic device 10 will be described, but the present invention is not limited to this example.

The hydraulic device 10 described below is a so-called variable displacement type swash plate type piston pump / motor, and can be used as both actuators for the pump and the motor. When the hydraulic device 10 is used as a pump, the hydraulic device 10 sucks the hydraulic oil into the cylinder chamber 21 described later and discharges the hydraulic oil from the cylinder chamber 21. On the other hand, when the hydraulic device 10 is used as a motor, the hydraulic device 10 outputs rotation from the shaft member 18 described later.

More specifically, when the hydraulic device 10 according to the embodiment described below is used as a pump, the shaft member 18 is rotated by power from a power source such as an engine, and is coupled to the shaft member 18 by spline coupling or the like. The cylinder block 20 is rotated. Due to the rotation of the cylinder block 20, the piston 25 housed in the cylinder chamber 21 of the cylinder block 20 reciprocates. In response to the reciprocating operation of the piston 25, the hydraulic oil is sucked into a part of the cylinder chambers 21 and the hydraulic oil is discharged from the other cylinder chambers 21.

On the other hand, when the hydraulic device 10 is used as a motor, the hydraulic oil is made to flow into the cylinder chamber 21 by using an external pump or the like, and the hydraulic oil is discharged from the other cylinder chamber 21. As a result, the piston 25 reciprocates in the cylinder chamber 21 and moves while sliding on the swash plate. The cylinder block 20 rotates with the operation of the piston 25, and the rotation can be output from the shaft member 18 fixed to the cylinder block 20.

The hydraulic device of the present embodiment can be typically used for a hydraulic circuit provided in a construction machine or a hydraulic device 10 as a drive device, but may be applied to other uses, and the use thereof is particularly limited. Not done.

As a specific example, FIG. 1 shows a hydraulic excavator 90 as an example of a construction machine CM to which the hydraulic device 10 according to the present embodiment can be applied. The hydraulic excavator 90 generally includes a lower frame 91 provided with a crawler, an upper frame 92 rotatably provided with respect to the lower frame 91, a boom 93 attached to the upper frame 92, and an arm 94 attached to the boom 93. , A bucket 95 attached to the arm 94. The hydraulic cylinders 96A, 96B, 96C are actuators for a boom, an arm, and a bucket, and drive the boom 93, the arm 94, and the bucket 95, respectively. Further, when the upper frame 92 is swiveled, the rotational driving force from the swivel device 97 is transmitted to the upper frame 92. Then, when the hydraulic excavator 90 is driven, the rotational driving force from the traveling device 98 is transmitted to the crawler of the lower frame 91. The swivel device 97 and the traveling device 98 are composed of a hydraulic motor that outputs rotation by inputting hydraulic pressure.

The hydraulic device 10 can be used as a pump that supplies pressure oil to hydraulic actuators such as the hydraulic cylinders 96A, 96B, 96C, the swivel device 97, and the traveling device 98. Further, the hydraulic device 10 may be applied to the swivel device 97 and the traveling device 98 so that the hydraulic system is supplied and the rotational driving force is output.

Next, the hydraulic device 10 will be described.

The hydraulic device 10 illustrated as a swash plate type has a case 15, a shaft member 18, a cylinder block 20, a piston 25, a valve plate 30, a tilt adjusting mechanism 35, and a swash plate 50 as main components. Hereinafter, each component will be described.

As shown in FIG. 2, the case 15 has a first case block 15a and a second case block 15b fixed to the first case block 15a. The first case block 15a and the second case block 15b are fixed to each other by using fasteners such as bolts. The case 15 forms a storage space S inside the case 15. A cylinder block 20, a piston 25, a valve plate 30, a tilt adjusting mechanism 35, and a swash plate 50 are arranged in the accommodation space S.

In the illustrated example, the valve plate 30 is arranged inside the first case block 15a. A first oil passage 11 and a second oil passage 12 are formed in the first case block 15a. The first oil passage 11 and the second oil passage 12 communicate with the cylinder chamber 21 of the cylinder block 20 via the valve plate 30. In the drawings, for convenience of explanation, the first oil passage 11 and the second oil passage 12 are represented by lines, but in reality, they are appropriate according to the supply and discharge of hydraulic oil to the cylinder chamber 21 of the cylinder block 20. Has a wide range of cross-sectional dimensions. The first oil passage 11 and the second oil passage 12 are provided so as to penetrate the case 15 from the inside of the case 15 to the outside of the case 15. The first oil passage 11 and the second oil passage 12 communicate with an actuator, a hydraulic source, or the like provided outside the hydraulic device 10.

The shaft member 18 is rotatably supported by the case 15 via bearings 19a and 19b. The shaft member 18 can rotate with its central axis as the rotation axis RA. One end of the shaft member 18 is rotatably supported by the first case block 15a via a bearing 19b. The other end of the shaft member 18 is rotatably supported by the second case block 15b via the bearing 19a, passes through a through hole provided in the second case block 15b, and extends out of the case 15. At the portion where the shaft member 18 penetrates the case 15, a seal member is provided between the case 15 and the shaft member 18 to prevent the hydraulic oil from flowing out of the case 15. The portion of the shaft member 18 extending from the case 15 is connected to an input means such as a motor or an engine.

The cylinder block 20 has a cylindrical or cylindrical shape arranged around the rotation axis RA. The cylinder block 20 is penetrated by a shaft member 18. The cylinder block 20 is connected to the shaft member 18 by, for example, a spline coupling. The cylinder block 20 can rotate about the rotation axis RA in synchronization with the shaft member 18.

A plurality of cylinder chambers 21 are formed in the cylinder block 20. The plurality of cylinder chambers 21 are arranged at equal intervals along the circumferential direction centered on the rotation axis RA. Each cylinder chamber 21 is open to the side of the swash plate 50 in the axial direction DA parallel to the rotation axis RA. In the illustrated example, each cylinder chamber 21 extends parallel to the axial DA. Further, a connection port CP is formed corresponding to each cylinder chamber 21. The connection port CP is open on the side of the valve plate 30 in the axial direction DA. Then, the connection port CP is connected to the corresponding cylinder chamber 21, and therefore, the cylinder chamber 21 is opened to the side of the valve plate 30 in the axial direction DA. The cylinder portion 21X is formed by the cylinder chamber 21 and the connection port CP. A plurality of cylinder portions are provided at intervals in the circumferential direction DC centered on the rotation axis RA. The cylinder chamber 21 and the connection port CP will be described in more detail later.

A piston 25 is provided corresponding to each cylinder chamber 21. A part of each piston 25 is arranged in the cylinder chamber 21. Each piston 25 extends axially DA from the corresponding cylinder chamber 21 toward the swash plate 50. The piston 25 can move in the axial direction DA with respect to the cylinder block 20. That is, the piston 25 can advance toward the swash plate 50 in the axial direction DA to increase the volume of the cylinder chamber 21. Further, the piston 25 can be retracted toward the valve plate 30 in the axial direction DA to reduce the volume of the cylinder chamber 21.

The swash plate 50 is supported in the case 15. The swash plate 50 is arranged in the axial direction DA so as to face the cylinder block 20 and the piston 25. As shown in FIG. 2, the shaft member 18 penetrates the central hole 51 of the swash plate 50. The swash plate 50 has a contact surface CS that comes into contact with the shoe 26 that rotates with the rotation of the shaft member 18. The contact surface CS is located so as to face the cylinder block 20 and the piston 25. The swash plate 50 is supported in the case 15 so that the contact surface CS can be inclined with respect to a surface perpendicular to the rotation axis RA.

As shown in FIG. 2, the shoe 26 is provided on the contact surface CS of the swash plate 50. The shoe 26 holds the end (head) of the piston 25. As a specific configuration, the end portion of the piston 25, which is one side end, is formed in a spherical shape. The shoe 26 has a hole that can accommodate approximately half of the spherical end. The shoe 26 holding the end of the piston 25 can move on the contact surface CS while contacting the contact surface CS of the swash plate 50.

The hydraulic device 10 further includes a retainer plate 27 arranged in the case 15. The retainer plate 27 is a ring-shaped and plate-shaped member. The retainer plate 27 is penetrated by the shaft member 18 and supported on the shaft member 18. The support portion 18a that supports the retainer plate 27 of the shaft member 18 is formed in a curved surface shape. Therefore, the retainer plate 27 can be turned while being supported on the shaft member 18. As shown in FIG. 2, the plate-shaped retainer plate 27 is inclined along the contact surface CS of the swash plate 50 and is in contact with the shoe 26.

Further, a piston pressing member 28 made of a spring or the like is provided between the shaft member 18 and the retainer plate 27. The piston pressing member 28 presses the retainer plate 27 toward the swash plate 50 in the axial direction DA. As a result, the retainer plate 27 can press the shoe 26 and the piston 25 toward the contact surface CS of the swash plate 50. Further, the piston pressing member 28 presses the shaft member 18 together with the cylinder block 20 toward the valve plate 30 in the axial direction DA. As a result, the cylinder block 20 is pressed toward the valve plate 30.

The valve plate 30 is fixed to the first case block 15a. That is, the valve plate 30 is stationary while the cylinder block 20 is rotating together with the shaft member 18. Two or more ports are formed on the valve plate 30. Each port communicates with the first oil passage 11 or the second oil passage 12. The port is formed along, for example, an arc centered on the rotation axis RA, and as the cylinder block 20 rotates, the port faces the connection port CP corresponding to each cylinder chamber 21 in order. As a result, each cylinder chamber 21 can switch the connection with the first oil passage 11 and the second oil passage 12 according to the rotation state of the cylinder block 20.

Here, FIG. 3 is a plan view showing the cylinder block 20 from the side of the valve plate 30 in the axial direction DA. That is, FIG. 3 shows a surface of the cylinder block 20 facing the valve plate 30, and a plurality of connection port CPs are opened on this surface. Further, in FIG. 3, the cylinder chamber 21 is shown by a dotted line. In the illustrated example, each connection port CP extends elongated in the circumferential direction DC about the rotation axis RA. In the observation from the side of the valve plate 30 in the axial DA shown in FIG. 3, each connection port CP overlaps the corresponding cylinder chamber 21 in its longitudinal central portion along the circumferential DC. On the other hand, each connection port CP is deviated from the corresponding cylinder chamber 21 in the circumferential direction DC at both end portions in the longitudinal direction along the circumferential direction DC.

In particular, in the example shown in FIG. 3, the position of the connection port CP along the radial DR orthogonal to the rotation axis RA is not constant. The connection port CPs arranged along the circumferential DC are alternately arranged at the inner position in the radial DR and the outer position in the radial DR. That is, the inner connecting port CPA located on the inner side in the radial direction and the outer connecting port CPB located on the outer side in the radial direction are alternately arranged in the circumferential direction DC. By changing the arrangement of the connection port CPs adjacent to the circumferential DC in the radial DR, it is possible to secure a long length of each connection port CP along the circumferential DC. By extending the connection port CP in the circumferential direction DC, it is possible to secure the connection between the connection port CP and the port of the valve plate 30 for a long period of time.

The inner side in the radial DR is the side close to the central axis RA in the radial DR, and the outer side in the radial DR is the side separated from the central axis RA in the radial DR.

Next, FIGS. 4A and 4B are plan views showing the valve plate 30 that can be used together with the cylinder block 20 shown in FIG. 3 from the accommodation space S. The valve plate 30 has a first port 31 connected to the first oil passage 11 and a second port 32 connected to the second oil passage 12. Both the first port 31 and the second port 32 extend in the circumferential direction DC. The range of the first port 31 and the second port 32 in the radial DR overlaps, at least in part, the range in which the connecting port CP is arranged in the radial DR. Therefore, the connection port CP is alternately connected to the first port 31 and the second port 32 by rotating the cylinder block 20.

In particular, in the example shown in FIG. 4A, the first port 31 leading to the first oil passage 11 has two first inner ports 31A and a first outer port having different positions in the radial DR. The first inner port 31A located inside in the radial DR can only communicate with the inner connection port CPA and is blocked from the first outer port 31B. On the other hand, the first outer port 31B located on the outer side in the radial DR can communicate only with the outer connection port CPB and is blocked from the first inner port 31A. In this example, the first oil passage 11 is also separated into two systems, one of the first oil passages 11 leads to the first inner port 31A, and the other of the first oil passage 11 connects to the first outer port 31B. I understand. On the other hand, both the inner connection port CPA and the outer connection port CPB can lead to the common second port 32 of the valve plate 30.

By using the valve plate 30 shown in FIG. 4A, for example, when the hydraulic device 10 is used as a pump, hydraulic oil can be discharged to the first oil passage 11 of two paths. For example, the hydraulic oil spilled from the inner connecting port CPA can be supplied to the first path of the first oil passage 11 via the first inner port 31A, and the hydraulic oil spilled from the outer connecting port CPB can be supplied to the first path. It can be supplied to a second path separated from the first path of the first oil passage 11 via the outer port 31B. Further, for example, when the hydraulic device 10 is used as a motor, the hydraulic oil flowing in from the first oil passage 11 of the two paths can be supplied to another cylinder chamber 21. For example, the hydraulic oil supplied from the first path of the first oil passage 11, for example, the hydraulic oil supplied from the first pump, is connected to the inner connection port CPA via the first inner port 31A into the cylinder chamber 21. Can be supplied. Further, the hydraulic oil supplied from the second path of the first oil passage 11, for example, the hydraulic oil supplied from the second pump is connected to the outer connection port CPB via the first outer port 31B into the cylinder chamber 21. Can be supplied.

On the other hand, in the example of the valve plate 30 shown in FIG. 4B, the first port 31 can communicate with both the inner connection port CPA and the outer connection port CPB, similarly to the second port 32.

Here, the operation of the hydraulic device 10 will be described. When the hydraulic device 10 functions as a pump, the shaft member 18 rotates about the rotation axis RA by a rotational driving force from an input means such as a motor or an engine (not shown). At this time, as the cylinder block 20 rotates, the piston 25 advances so as to protrude from the cylinder block 20 and then retracts into the cylinder block 20. The volume of the cylinder chamber 21 changes due to the advance / retreat operation of the piston 25.

While the piston 25 retracts from the position where it extends most from the cylinder chamber 21 (top dead center) to the position where it enters the cylinder chamber 21 most (bottom dead center), the cylinder chamber 21 accommodating the piston 25 Capacity is reduced. During this period, the cylinder chamber 21 accommodating the retracting piston 25 is connected to, for example, the first oil passage 11 via the connection port CP and the first port 31 of the valve plate 30 from the cylinder chamber 21. Discharge hydraulic oil. The first oil passage 11 is connected to an external actuator or the like as a flow path on the high pressure side.

On the other hand, while the piston 25 advances from the bottom dead center to the top dead center, the capacity of the cylinder chamber 21 accommodating the piston 25 increases. During this period, the cylinder chamber 21 accommodating the moving piston 25 is connected to, for example, the second oil passage 12 via the connection port CP and the second port 32 of the valve plate 30, and is inside the cylinder chamber 21. Aspirate hydraulic oil. The second oil passage 12 is connected to a tank or the like for storing hydraulic oil as a flow path on the low pressure side.

When the hydraulic device 10 functions as a hydraulic motor, the hydraulic oil discharged from an external pump (not shown) to the first oil passage 11 is supplied to the hydraulic device 10 via the first port 31 of the valve plate 30 and the connection port CP. It is supplied into the cylinder chamber 21. The piston 25 in the cylinder chamber 21 to which the hydraulic oil is supplied can advance so as to extend from the cylinder block 20. Therefore, the first port 31 of the valve plate 30 connects the cylinder chamber 21 located in the path from the bottom dead center to the top dead center of the housed piston 25 to the first oil passage 11 on the high pressure side. In this way, the cylinder block 20 can be rotated by supplying hydraulic oil from the external pump, and the rotational force can be output via the shaft member 18.

The second port 32 of the valve plate 30 connects the cylinder chamber 21 located in the path from the top dead center to the bottom dead center of the housed piston 25 to the second oil passage 12 on the low pressure side. Therefore, while the piston 25 retreats from the top dead center to the bottom dead center, the hydraulic oil in the cylinder chamber 21 accommodating the piston 25 is seconded through the connection port CP and the second port 32 of the valve plate 30. It can be discharged to the oil passage 12. The hydraulic oil discharged from the hydraulic device 10 is collected in a tank or the like connected to the second oil passage 12.

In the above hydraulic device 10, the contact surface CS of the swash plate 50 limits the amount of protrusion of the piston 25 from the cylinder block 20. Therefore, the inclination of the swash plate 50, more precisely expressed, depends on the magnitude of the inclination angle θi (see FIG. 2) of the contact surface CS of the swash plate 50 with respect to the surface perpendicular to the axial direction DA. The reciprocating stroke of the piston 25 along the direction DA is determined. Then, the output of the hydraulic device 10 can be changed by changing the inclination of the swash plate 50, that is, by inclining the swash plate 50. Specifically, when the inclination of the swash plate 50 becomes large, in other words, when the inclination angle θi becomes large, the output of the hydraulic device 10 increases. When the inclination of the swash plate 50 becomes small, in other words, when the inclination angle θi becomes small, the output of the hydraulic device 10 decreases. When the contact surface CS of the swash plate 50 becomes perpendicular to the axial direction DA, that is, when the inclination angle θi becomes 0 °, theoretically, no output can be obtained from the hydraulic device 10.

Therefore, in the illustrated hydraulic device 10, the swash plate 50 is held so as to be tiltable. The tilt adjusting mechanism 35 includes a swash plate pressing member 36 and a swash plate driving device 37. The swash plate pressing member 36 and the swash plate driving device 37 are arranged in the case 15 so as to sandwich the shaft member 18 so as to be separated in the radial DR. The swash plate pressing member 36 pushes the swash plate 50 so that the inclination angle θi becomes large, and in particular, the swash plate 50 rotates counterclockwise in FIG. The swash plate driving device 37 pushes the swash plate 50 so that the inclination angle θi becomes small, and in particular, the swash plate 50 rotates clockwise in FIG. The output from the swash plate drive device 37 can be adjusted. By adjusting the output from the swash plate driving device 37, the inclination angle θi of the swash plate 50 can be controlled.

By the way, in the illustrated example, in the observation from the side of the valve plate 30 in the axial direction DA, the connection port CP extends along the circumferential direction DC (see FIG. 3). Therefore, it is possible to stably secure the connection between each cylinder chamber 21 of the cylinder block 20 rotating at high speed and the ports 31 and 32 of the valve plate 30. On the other hand, in the observation from the valve plate 30 side in the axial direction DA, the connection port CP elongated in the circumferential direction DC partially overlaps the cylinder chamber 21, but is partially displaced from the cylinder chamber 21. .. That is, when observed from the valve plate 30 side in the axial direction DA, the connection port CP elongated in the circumferential direction DC has a shape protruding from the cylinder chamber in the circumferential direction DC. In other words, as shown in FIG. 3, in the projection to the axial DA, the connection port CP partially overlaps with the corresponding cylinder chamber 21 and does not overlap with the cylinder chamber 21 in other parts. Further, the connection port CP is not limited to the connection port CP having a shape extending in the circumferential direction DC, and for example, due to the positional relationship of the valve plate 30 with the ports 31 and 32, etc., in the observation from the valve plate 30 side in the axial direction DA. , The connection port CP may be located at least partially offset from the cylinder chamber 21.

Here, in the cylinder block 120 shown in FIG. 13, the connection port CP is extended from the cylinder chamber 121 via a step. That is, a port bottom surface portion PB facing the valve plate side in the axial direction DA is provided between the port wall surface portion PW of the connection port CP and the cylinder wall surface portion CW of the cylinder chamber 121. The bottom surface portion PB of the port extends in a direction substantially orthogonal to the axial direction DA.

However, in the example shown in FIG. 13, it is difficult for the hydraulic oil to smoothly flow between the cylinder chamber 121 and the expanded portion via the step of the connection port CP. On the contrary, in the vicinity of the port wall surface portion PW and the port bottom surface portion PB, the hydraulic oil flow may be greatly disturbed or the hydraulic oil flow may be stagnant. In the cylinder chamber 121 on the low pressure side, for example, in the cylinder chamber 121 on the low pressure side of the hydraulic device 110 used as a pump, the smooth flow of hydraulic oil is hindered, the pressure drops, and cavitation may occur. When cavitation occurs and air bubbles are generated, the flow of hydraulic oil becomes more and more stagnant, causing abnormal noise and erosion. On the other hand, in the cylinder chamber 121 on the high pressure side, between the connection port CP and the cylinder chamber 121. Pressure loss occurs in the flow of hydraulic oil in. The pressure loss in such a flow path deteriorates the performance of the hydraulic device 110 used as a pump or a motor, and it becomes difficult to obtain the expected output from the hydraulic device 110.

On the other hand, according to the present embodiment, a device is made to facilitate the flow between the cylinder chamber 21 and the connection port CP. Hereinafter, this device will be described with reference mainly to FIGS. 5 to 12. Here, FIG. 5 is a cross-sectional view showing a cross section taken along the line VV in FIG. That is, FIG. 5 is a cross-sectional view showing the cylinder block 20 in a cross section along the longitudinal direction of the inner connection port CPA. Further, FIG. 6 is a cross-sectional view showing a cross section taken along the line VI-VI in FIG. That is, FIG. 6 is a cross-sectional view showing the cylinder block 20 in a cross section along the longitudinal direction of the outer connection port CPB.

First, as shown in FIGS. 2 and 3, the cylinder chamber 21 has a substantially columnar inner shape. The cylinder chamber 21 is partitioned (formed) by a cylinder wall surface portion CW corresponding to the side surface of the cylinder and a cylinder bottom surface portion CB corresponding to the bottom surface of the cylinder. The cylinder bottom surface CB faces the swash plate 50 side in the axial direction DA. In the illustrated example, the cylinder wall surface CW extends parallel to the rotation axis RA, and the cylinder bottom surface CB is typically orthogonal to the rotation axis RA.

On the other hand, as described above, the connection port CP extends linearly in the circumferential direction DC and opens to the side of the valve plate 30 in the axial direction DA. The connection port CP has a port wall surface portion PW extending in parallel with the rotation axis RA. Further, the connection port CP is partially displaced from the cylinder chamber 21 in the observation from the valve plate 30 side in the axial direction DA shown in FIG. The connection port CP has a port bottom surface PB at a position deviated from the cylinder chamber 21. The bottom surface of the port PB is typically orthogonal to the axis of rotation RA.

Further, as shown in FIGS. 5 and 6, the connection port CP communicates with the cylinder chamber 21 via the opening OP on the side of the swash plate 50 in the axial direction DA. Then, in the present embodiment, the cylinder block 20 has an inclined surface portion IS. The inclined surface portion IS is connected to at least a part of the port wall surface portion PW located offset from the cylinder chamber 21 in the direction orthogonal to the axial direction DA and the cylinder wall surface portion CW. The inclined surface portion IS faces the valve plate 30 side in the axial direction DA. That is, in the present embodiment, the port wall surface portion PW of the connection port CP and the cylinder wall surface portion CW of the cylinder chamber 21 can be smoothly connected via the inclined surface portion IS. By connecting the cylinder wall surface portion CW and the port wall surface portion PW at least partially via the inclined surface portion IS, the flow of hydraulic oil between the cylinder chamber 21 and the connection port CP is smoothed. Can be done. As a result, when the hydraulic device 10 is applied to the pump, the hydraulic oil can be stably drawn into the cylinder chamber 21 on the low pressure side. As a result, the self-absorption property is improved, and problems such as the occurrence of cavitation can be effectively avoided. Further, when the hydraulic device 10 is applied to the motor and the pump, the pressure loss of the hydraulic oil flowing between the connection port CP and the cylinder chamber 21 can be effectively avoided. As a result, the performance of the hydraulic device 10 utilized as a motor or a pump can be improved.

The port bottom surface PB and the cylinder bottom surface CB are typically planes perpendicular to the axial direction DA, but may be inclined without being orthogonal to the axial direction DA depending on machining conditions and the like. There is also. However, the angles formed by the port bottom surface PB and the cylinder bottom surface CB with respect to the plane orthogonal to the rotation axis RA are very small. The angle formed by the inclined surface portion IS with respect to the surface orthogonal to the axial direction DA is larger than the angle formed by the cylinder bottom surface portion CB with respect to the surface orthogonal to the axial direction DA, and the port bottom surface portion PB is formed with the axial direction DA. Greater than the angle formed with respect to orthogonal planes.

In the hydraulic device 10 applied as a pump or a motor, the inclination angle θx (see FIG. 5) formed by the inclined surface portion IS with respect to the axial direction DA is preferably 30 ° or more and 70 ° or less. When the inclination angle θx is large, it becomes difficult to sufficiently effectively smooth the flow of hydraulic oil between the cylinder chamber 21 and the connection port CP, as in the example of FIG. On the other hand, when the inclination angle θx is small, the length of the cylinder block 20 in the axial direction becomes long, and the machining conditions become strict.

As shown in FIGS. 5 and 6, the illustrated cylinder block 20 has a plurality of inclined surface portions IS arranged apart from each other. A port bottom surface portion PB is provided between the plurality of inclined surface portions IS. As shown in FIG. 3, in the observation from the valve plate 30 side in the axial direction DA, the port bottom surface portion PB is located offset from the cylinder chamber 21 in the direction orthogonal to the axial direction DA. As shown in FIGS. 5 and 6, the angle formed by the inclined surface portion IS with respect to the surface orthogonal to the axial direction DA is larger than the angle formed by the port bottom surface portion PB with respect to the surface orthogonal to the axial direction DA. There is.

As described above, the illustrated connection port CP extends linearly, especially in an arc shape, when observed from the side of the valve plate 30 in the axial DA. As shown in FIGS. 5 and 6, the connection port CP does not overlap the cylinder chamber 21 and the axial DA at its longitudinal end, especially at both ends. The connection port CP has inclined surface portions IS at both ends thereof. Further, the inner connection port CPA shown in FIG. 5 has an inclined surface portion IS in an intermediate portion between both end portions in addition to both end portions in the observation from the valve plate 30 side in the axial direction DA. ..

In the illustrated example, the inclined surface portion IS has a shape corresponding to at least a part of the surface of a rotating body that tapers from the side of the valve plate 30 to the side of the inclined plate 50 in the axial direction DA. Typically, the inclined surface portion IS has a shape corresponding to a part of the side surface of the cone as a triangular rotating body. As will be described later, the inclined surface portion IS having such a shape can be easily and highly accurately manufactured.

The roughness of the port wall surface portion PW may be made smaller than the roughness of the inclined surface portion IS. Further, the roughness of the cylinder wall surface portion CW may be made smaller than the roughness of the inclined surface portion IS. When the port wall surface portion PW and the cylinder wall surface portion CW are planes parallel to the axial direction DA, the port wall surface portion PW and the cylinder wall surface portion CW can be easily finished. By making the roughness of the port wall surface PW and the roughness of the cylinder wall surface CW smaller than the roughness of the inclined surface IS by finishing, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be prevented. It can be smoothed more effectively. The roughness is evaluated to be smaller as the value of the arithmetic mean roughness Ra measured in accordance with JIS B 0601-2001 is smaller.

Next, an example of a method for manufacturing the cylinder block 20 will be described with reference to FIGS. 7 to 10. In the following manufacturing method, the cylinder block 20 is manufactured by forming the cylinder chamber 21 and the connection port CP in the base material W. 7 to 10 show a method of forming the cylinder chamber 21 and the inner connection port CPA in the same cross section as that of FIG.

The inventors of the present invention have also considered manufacturing a cylinder block 20 including the above-mentioned inclined surface portion IS by diagonal cutting or casting using a core. However, depending on the shape and dimensions of the cylinder block 20, diagonal cutting and manufacturing of cores have become difficult. That is, in diagonal cutting or casting using a core, the cylinder block 20 including the inclined surface portion IS could not be manufactured sufficiently stably according to the present embodiment. Then, as a result of further diligent studies, the inventors of the present invention have come to find a manufacturing method described below.

First, the base material W that forms the cylinder block 20 is prepared. The base material W is made of steel by casting, for example. The original material W produced by casting has an outer shape similar to that of the cylinder block 20 to be finally produced. However, in the examples shown in FIGS. 7 to 9, the cylinder chamber 21 and the connection port CP are not formed in the base material W.

Next, as shown in FIG. 7, the base material W is cut using a processing tool 60 having a tapered tip portion 60a. A drill can be used as the processing tool 60. As shown in FIG. 7, while rotating the processing tool 60, it advances from the other side to one side in the one-way DX to cut the original material W. At this time, the processing tool 60 is rotated about an axis parallel to the unidirectional DX, and is advanced along this axis to cut into the original material W. In the base material W, a first hole HA opened on the other side in the one-way DX is formed. The first hole HA comes to have the shape of a rotating body (typically a cone) that tapers toward one side in the one-way DX at the one-sided end in the one-way DX. That is, the one-sided end of the first hole HA in the unidirectional DX has an inclined surface HAS having the same shape as the surface of the tapered rotating body (typically a cone). A part of the inclined surface HAS remains to form the inclined surface portion IS of the cylinder block 20 described above. In the example shown in FIG. 7, a plurality of holes separated from each other, particularly three first hole HAs, are formed in the base material W.

The one-way DX referred to in this manufacturing method is a direction parallel to the axial direction DA with respect to the above-mentioned cylinder block 20 in a state of being incorporated in the hydraulic device 10. Further, the one side in the one-way DX corresponds to the side of the swash plate 50 in the axial direction DA with respect to the cylinder block 20 in the state of being incorporated in the hydraulic device 10. The other side in the one-way DX corresponds to the side of the valve plate 30 in the axial DA with respect to the cylinder block 20 in the state of being incorporated in the hydraulic device 10.

After that, as shown in FIG. 8, the base material W is processed by using a processing tool (second processing tool) 61 which is different from the processing tool (first processing tool) 60. More specifically, the base material W is processed using a processing tool 61 having a flat tip, for example, an end mill, using a multi-tasking machine or the like. In this step, the outer shape of the connection port CP extending linearly, typically curvedly, is generally formed. First. As shown by the dotted line in FIG. 8, the processing tool 61 is advanced along this axis while rotating the processing tool 61 () around an axis parallel to the unidirectional DX, and the processing tool 61 is formed on the base material W. It is inserted into one first hole HA. At this time, the hole formed by the processing tool 61 is the same as or slightly larger than the first hole HA formed by the processing tool 60. Next, the machining tool 61 is advanced in a direction non-parallel to the unidirectional DX (direction of intersection), typically in a direction orthogonal to the unidirectional DX. Here, the processing tool 61 () can process the original material W by moving in a direction different from the one-way DX (typically, a direction orthogonal to the one-way DX) in addition to the one-way DX. Is. Specifically, the machining tool 61 is moved from the position shown by the dotted line in FIG. 8 to the position shown by the alternate long and short dash line in FIG. 8 via the position shown by the solid line in FIG. In the observation from the axial direction DA, the movement path of the processing tool 61 corresponds to the path of the connection port CP and has an arc shape centered on the rotation axis RA. By such movement of the processing tool 61, the portion of the original material W between the plurality of first holes HA is removed by cutting.

In the example shown in FIG. 7, the machining tool 61 moves between the plurality of first hole HAs provided. In particular, the processing tool 61 moves between both ends of the three first hole HAs provided via the intermediate first hole HA. As a result, a second hole HB extending linearly (curved in the illustrated example) is formed, and the second hole HB has a shape generally similar to that of the connection port CP to be manufactured. Further, both ends of the second hole HB (in the illustrated example, both ends of the circumferential direction DC of the second hole HB) and the center position have the same shape as the surface of the rotating body (typically a cone) that tapers. The inclined surface HAS of the first hole HA is left.

In the process shown in FIG. 8, the processing tool (second processing tool, other processing tool) 61 may also serve as finishing processing. When the processing using the processing tool 61 also serves as the finishing processing, the port wall surface portion PW of the connection port CP is formed by the processing tool 61, and the roughness of the port wall surface portion PW is determined by the first hole before this step. It can be made smaller than the roughness of the surface extending in one direction DX of HA. As a result, the roughness of the port wall surface portion PW of the connection port CP can be made smaller than the roughness of the inclined surface HAS of the first hole HA.

After that, as shown in FIG. 9, the base material W is cut from one side in the one-way DX to form a cylinder chamber 21 that opens to one side in the one-way DX. In this step, a cutting tool 62 including an end mill or a drill can be used. The cylinder chamber 21 can be formed by advancing the cutting tool 62 along the axis while rotating the cutting tool 62 around an axis parallel to the unidirectional DX. At this time, the cutting tool 62 is advanced to a position where it overlaps with the second hole HB in the one-way DX. The cylinder chamber 21 and the connection port CP formed in this way are formed, and the cylinder chamber 21 communicates with the connection port CP.

However, as described with reference to FIG. 3, in the observation from the other side in the one-way DX, the connection port CP is located at least partially deviated from the cylinder chamber 21 in the direction orthogonal to the one-way DX. .. The inclined surface HAS of the first hole HA is included at a position deviated from the cylinder chamber 21. As a result, a cylinder chamber 21 that is connected to the second hole HB (connection port CP) is formed on the inclined surface HAS. As described above, the inclined surface portion IS is formed by the remaining portion of the inclined surface HAS, and finally, the inner connection port CPA and the cylinder chamber 21 shown in FIG. 5 can be formed. ..

Further, by going through the same steps as the method described above, the outer connection port CPB and the cylinder chamber 21 shown in FIG. 6 can be formed. However, it differs from the method of forming the inner connection port CPA in that the system method of the outer connection port CPB and the formation position of the first hole HA are shifted outward in the radial direction and only two first hole HAs are formed. In addition, in FIG. 6, the processing tool 60 used for forming the first hole HA is shown by a chain double-dashed line. In the outer connection port CPB shown in FIG. 6, the portion of the connection port CP located offset from the cylinder chamber 21 in the observation in the axial direction DA is smaller than that in the inner connection port CPA shown in FIG. Become. As a result, the outer connection port CPB has a smaller inclined surface portion IS than the inner connection port CPA.

The manufacturing method described above is an example of the method for manufacturing the cylinder block 20 described above, and can be changed. For example, after processing with the processing tool 61 (second processing tool, other processing tool), the port wall surface portion PW of the connection port CP and the cylinder wall surface of the cylinder chamber 21 are further used with the processing tool for finishing processing. The part CW may be finished. Finishing of the port wall surface PW and the cylinder wall surface CW extending in one-way DX can be performed relatively easily. By finishing, the roughness of the port wall surface PW and the cylinder wall surface CW can be reduced, thereby more effectively smoothing the flow of hydraulic oil between the connection port CP and the cylinder chamber 21. Can be done.

Further, in the above-described embodiment, an example is shown in which the processing for forming the first hole HA, the processing for forming the second hole HB, and the processing for forming the cylinder chamber 21 are performed in this order. However, the present invention is not limited to this example, and the order of the processing for forming the first hole HA, the processing for forming the second hole HB, and the processing for forming the cylinder chamber 21 can be appropriately changed.

For example, the cylinder chamber 21 is first formed in the base material W, and the first hole HA is formed in the base material W in which the cylinder chamber 21 is formed by using the processing tool 60 as shown in FIG. You may do so. In the example shown in FIG. 10, two first hole HAs are formed by the processing tool 60 shown by the dotted line with respect to the original material W in which the cylinder chamber 21 is formed. Further, in this example, by moving the processing tool 60 indicated by the solid line to the position indicated by the alternate long and short dash line in one direction DX, the third first hole HA indicated by the alternate long and short dash line is formed. Further, in the example shown in FIG. 10, a step of expanding the first hole HA by using the processing tool 61 with respect to the base material W in which the cylinder chamber 21 and the first hole HA are formed is formed to produce a connection port CP. Will be implemented.

Further, in the example described with reference to FIG. 10, the cylinder chamber 21 may not be formed by cutting the base material W, and the cylinder chamber 21 may be formed by casting. That is, the original material W shown in FIG. 10 may be cast in a shape in which the recess 21A forming the cylinder chamber 21 is formed.

Further, as shown in FIG. 11, after forming the first hole HA by using the processing tool 60 having the tapered tip portion 60a, the processing tool 60 cut into the base material W is not parallel to the unidirectional DX. The second hole HB may be formed by moving in a direction (typically, a direction orthogonal to the one-way DX). After that, the connection port CP and the cylinder chamber 21 shown in FIG. 12 can be formed through the step of forming the cylinder chamber 21 in the base material W. FIG. 12 is a view corresponding to FIG. 5, and shows the cylinder block 20 in a cross section along the VV line of FIG. In the example shown in FIG. 12, the inclined surface portion IS extends linearly in the observation from the other side in the axial direction DA. Then, the inclined surface portion IS extending linearly when observed from the other side in the axial direction DA has the same shape as the surface of the tapered rotating body (typically a cone) at both end portions of the first hole HA. The sloping surface HAS remains. Further, the inclined surface portion IS extending linearly when observed from the other side in the axial direction DA has a constant inclination angle corresponding to the tip portion 60a of the processing tool 60 at each position of the intermediate portion between the both end portions thereof. It will have an inclined inclined surface HAS.

In one embodiment described above, the cylinder block 20 is a cylinder wall surface portion that extends in one direction DX (axial DA) and forms a cylinder chamber 21 that is open on one side in one direction DX (axial DA). The CW and the cylinder bottom surface CB, the port wall surface PW that opens to the other side in the one-way DX and forms the connection port CP that leads to the cylinder chamber 21, and the inclined surface portion that is inclined with respect to the one-way DX (axial DA). Has IS and. The inclined surface portion IS is connected to at least a part of the port wall surface portion PW located offset from the cylinder chamber 21 in a direction orthogonal to the unidirectional DX (axial direction DA) and the cylinder wall surface portion CW. According to this embodiment, the port wall surface portion PW of the connection port CP and the port wall surface portion PW of the cylinder chamber 21 can be smoothly connected via the inclined surface portion IS. Therefore, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be effectively smoothed. As a result, in the pump, the hydraulic oil can be stably drawn into the cylinder chamber 21 on the low pressure side. As a result, the self-absorption property is improved, and problems such as the occurrence of cavitation can be effectively avoided. Further, in the motor, the pressure loss of the hydraulic oil flowing between the connection port CP and the cylinder chamber 21 can be effectively avoided. As a result, the performance of the hydraulic device 10 can be improved.

In one specific example of the above-described embodiment, at least a part of the inclined surface portion IS has a shape forming a part of the side surface of the cone. According to this specific example, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 is effectively avoided from being disturbed, and the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 is further increased. Can be effectively smoothed.

In one specific example of the above-described embodiment, the connection port CP has a shape protruding from the cylinder chamber in the circumferential direction DC. In other words, in observation from the other side in the axial DA (one-way DX), the connection port CP extends linearly and is located at the end offset from the cylinder chamber 21, and the inclined surface IS is the end of the connection port CP. It is provided at the position where According to this specific example, for example, the connection port CP can have an elongated shape along the ports 31 and 32 formed on the valve plate 30. Therefore, the flow of hydraulic oil between the connection port CP and the valve plate 30 can be smoothed. Further, since the inclined surface portion IS is provided at the end of the elongated connection port CP, it is possible to effectively avoid the flow of hydraulic oil from being disturbed at the end of the elongated connection port CP, and the connection port CP and the cylinder chamber 21. The flow of hydraulic oil to and from can be smoothed more effectively.

In one specific example of the above-described embodiment, the inclined surface portion IS has an angle of 30 ° or more and 70 ° or less with respect to the axial DA (unidirectional DX). According to this specific example, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be smoothed more effectively.

In one specific example of the above-described embodiment, the roughness of the port wall surface portion PW is smaller than the roughness of the inclined surface portion IS. According to this specific example, the roughness of the port wall surface portion PW of the connection port CP can be reduced. This makes it possible to more effectively smooth the flow of hydraulic oil between the connection port CP and the cylinder chamber 21.

In one specific example of the above-described embodiment, a plurality of inclined surface portions IS are provided so as to be separated from each other. According to this specific example, a plurality of inclined surface portions IS are provided in a dispersed manner. Therefore, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be smoothed more effectively.

In one specific example of the above-described embodiment, the inclined surface portion IS extends linearly in the observation from the other side in the one-way DX (axial direction DA). According to this specific example, since the inclined surface portion IS is provided over a wide range, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be more effectively smoothed.

In one specific example of the above-described embodiment, the inclined surface portion IS extending linearly when observed from the other side in the unidirectional DX (axial direction DA) has a shape forming a part of the side surface of the cone at both ends thereof. Have. According to this specific example, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 is effectively avoided from being disturbed, and the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 is further increased. Can be effectively smoothed.

In one embodiment described above, in the method of manufacturing a cylinder block, a processing tool 60 having a tapered tip portion 60a is advanced to one side in one-way DX (axial direction DA), and one-way DX (axial direction) is used. A step of forming a first hole HA on the base material W, which includes an inclined surface HAS inclined with respect to DA) and is open to the other side in one-way DX, and a base material W from one side in one-way DX (axial DA). The step of forming a cylinder chamber 21 to be connected to the holes HA and HB on the inclined surface HAS is included. Alternatively, in one embodiment, a processing tool 60 having, for example, a casting step and a tapered tip portion 60a for producing a base material W including a cylinder chamber 21 opened on one side in one direction DX (axial direction DA). In the step of forming a hole HA including an inclined surface HAS inclined with respect to the one-way DX and connected to the cylinder chamber 21 in the base material W by advancing from the other side to one side in the one-way DX (axial direction DA). ,including. According to such an embodiment, the port wall surface portion PW of the connection port CP formed by the holes HA and HB and the cylinder wall surface portion CW of the cylinder chamber 21 are smoothly connected via the inclined surface portion IS. Can be done. Therefore, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be effectively smoothed. As a result, in the pump, the hydraulic oil can be stably drawn into the cylinder chamber 21 on the low pressure side. As a result, the self-absorption property is improved, and problems such as the occurrence of cavitation can be effectively avoided. Further, in the motor, the pressure loss of the hydraulic oil flowing between the connection port CP and the cylinder chamber 21 can be effectively avoided. As a result, pump performance can be improved.

In one specific example of the above-described embodiment, in the step of forming the first hole HA, a plurality of first hole HAs separated from each other are formed. According to this specific example, a plurality of inclined surface portions IS are provided in a dispersed manner. Therefore, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be smoothed more effectively.

In one specific example of the above-described embodiment, the method of manufacturing the cylinder block is to move the end mill 61 in a direction non-parallel to the unidirectional DX (axial DA) so as to leave the inclined surface HAS at least partially. The step of cutting between the plurality of first holes HA of the original material W is further included. According to this specific example, the cross-sectional area of the connection port CP formed by the holes HA and HB can be increased. Therefore, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be smoothed more effectively.

In one specific example of the above-described embodiment, the roughness of the surface formed by using the end mill 61 is smaller than the roughness of the inclined surface HAS formed by using the processing tool 60. According to this specific example, the roughness of the port wall surface portion PW of the connection port CP formed by the holes HA and HB can be reduced. This makes it possible to more effectively smooth the flow of hydraulic oil between the connection port CP and the cylinder chamber 21.

In one specific example of the above-described embodiment, the method for manufacturing a cylinder block further includes a step of moving the processing tool 60 in a direction non-parallel to the unidirectional DX (axial direction DA) to widen the holes HA and HB. .. According to this specific example, since the inclined surface portion IS is formed over a wide range, the flow of hydraulic oil between the connection port CP and the cylinder chamber 21 can be more effectively smoothed.

Although one embodiment has been described by a plurality of specific examples, these specific examples are not intended to limit one embodiment. The above-described embodiment can be implemented in various other specific examples, and various omissions, replacements, changes, additions, and the like can be made without departing from the gist thereof.

10 Hydraulic device 20 Cylinder block 21 Cylinder chamber 60 Machining tool, 1st machining tool 60a Tip 61 Machining tool, 2nd machining tool, other machining tools 62 Cutting tool CW Cylinder wall surface CB Cylinder bottom CP connection port CPA Inside Connection port CPB Outer connection port PW port Wall surface PB Port bottom IS Inclined surface HA 1st hole HB 2nd hole HAS Inclined surface HAS
CM Construction Machinery DX One Direction W Original Material

Claims (15)

A cylinder wall surface portion formed along one direction and forming a cylinder chamber opened on one side in the one direction.
A cylinder end face portion formed on the other side of the cylinder wall surface portion in the one direction and having an opening at least in a part thereof.
A port wall surface that connects to the opening and forms a connection port that is located offset from the cylinder chamber in a direction orthogonal to the one direction.
A plurality of cylinder portions including at least a part of the port wall surface portion and at least a part of the cylinder wall surface portion and having an inclined surface portion inclined with respect to one direction are arranged in the circumferential direction about the rotation axis. Cylinder block. The cylinder block according to claim 1, wherein at least a part of the inclined surface portion has a shape forming a part of a side surface portion of the cone. The cylinder block according to claim 1 or 2, wherein the connection port has a shape protruding from the cylinder chamber in the circumferential direction of the cylinder block. The cylinder block according to any one of claims 1 to 3, wherein the inclined surface portion has an angle of 30 ° or more and 70 ° or less with respect to the one direction. The cylinder block according to any one of claims 1 to 4, wherein the roughness of the port wall surface portion is smaller than the roughness of the inclined surface portion. The cylinder block according to any one of claims 1 to 5, wherein a plurality of inclined surface portions separated from each other are connected to one cylinder wall surface portion. A cylinder wall surface portion provided at intervals in the circumferential direction centered on an axis along one direction and each forming a plurality of cylinder chambers opened on one side in the one direction.
A cylinder end face connected to the cylinder wall surface from the other side in one direction,
A port wall surface that forms a connection port leading to the cylinder chamber,
An inclined surface portion that connects at least a part of the port wall surface portion and at least a part of the cylinder wall surface portion and is inclined with respect to the one direction is provided.
At least a part of the inclined surface portion has a shape forming a part of the side surface portion of the cone.
In the circumferential direction, the connection port has a shape protruding from the cylinder chamber.
The inclined surface portion is a cylinder block having an angle of 30 ° or more and 70 ° or less with respect to the one direction. A hydraulic device comprising the cylinder block according to any one of claims 1 to 7. A construction machine comprising the hydraulic device according to claim 8. A step of advancing a processing tool having a tapered tip portion to one side in one direction to form a hole in the base material including an inclined surface portion inclined with respect to the one direction and opening to the other side in the one direction.
A method for manufacturing a cylinder block, comprising a step of cutting the base material from the one side in the one direction to form a cylinder chamber to be connected to the hole in the inclined surface portion. The process of producing the base material including the cylinder chamber opened on one side in one direction,
A step of advancing a processing tool having a tapered tip portion from the other side in the one direction to the one side, and forming a hole including an inclined surface portion inclined in the one direction and connected to the cylinder chamber in the base material. And, a method of manufacturing a cylinder block. The method for manufacturing a cylinder block according to claim 10 or 11, wherein a plurality of holes separated from each other are formed in the step of forming the holes. The twelfth aspect of claim 12, further comprising a step of moving another processing tool in a direction intersecting the one direction, leaving the inclined surface portion at least partially, and cutting between the plurality of holes of the original material. Cylinder block manufacturing method. The method for manufacturing a cylinder block according to claim 13, wherein the roughness of the surface formed by using the other processing tool is smaller than the roughness of the inclined surface portion formed by using the processing tool. The method for manufacturing a cylinder block according to claim 10 or 11, further comprising a step of moving the other processing tool in a direction intersecting the one direction to widen the hole.