JPH10184968A - Valve housing structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase valve housing yield by separately manufacturing a spool pipe guide, a pressure control valve guide and a flow rate control valve pipe guide, connecting each pipe guide with a core so as to assemble the core of the valve housing and assembling and forging this in a matrix. SOLUTION: For manufacturing a control valve housing, first oil passage cores 440, 443a, 443b, 444a, 444b, 450a, 450b and 441 are molded by sand dies as conventionally. Then, the oil passages of the cores are properly connected to a spool pipe guide 14, a pressure compensation valve pipe guide 22 and a makeup valve pipe guide 32. Then, the connected cores are assembled in an upper and lower pair of matrixes, a cooling blower 450 is attached to one end of the spool pipe guide 14 and exhaust flange ports 451 to 455 are installed in the closed part of the other end, the pressure compensation pipe guide 22 and the makeup valve pipe guide 32. Then, a valve housing is formed by forging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and structure for manufacturing a valve housing having a complicated flow path therein, and more particularly to a method suitable for manufacturing a control valve for hydraulic equipment which has been conventionally formed by casting. The present invention relates to a housing structure and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a conventional method of producing a valve, a control valve used in hydraulic equipment will be described as an example.

[0003] Conventional control valve constructions typically have as many spools as actuators inside the valve. The control valve, which controls meter-in and meter-out at the same time, has four or more oil passages: a supply port for hydraulic oil to the spool, an input / output port to the actuator, and a return port to the hydraulic oil tank.

As an example of such a control valve, there is a control valve described in Japanese Patent Application Laid-Open No. 5-288204. In this control valve, the hydraulic oil flows out to the motor of the actuator when the spool that switches the direction of the hydraulic oil supplied from the pump moves. The hydraulic oil returned from the actuator flows again through the suburb to the hydraulic oil tank, passes through the subboat, and flows into the tank. In addition, a boat that detects load pressure, a makeup valve that supplies hydraulic oil when the meter-in side becomes negative pressure,
The boat of the pressure regulating valve is complicatedly intertwined. For example, there are six actuators in a hydraulic shovel, and more and more similar structures are arranged in a row, which is becoming more complicated.

Since the control valve housing is formed by a body, the internal oil passage is complicated, and it is difficult to cut out a metal lump by machining to form the control valve housing in terms of cost and structure. As a result, it is almost always produced by casting.
In the production by casting, an oil passage to be formed is formed by a core, which is incorporated into a matrix, and cast iron is poured. The core has a complicated three-dimensional shape because it connects the oil passage, spool, and other valves, and is manufactured by dividing it into several parts and bonding them with an adhesive. The control valve housing is completed by removing the core with air or the like while the casting is cooled and hardened, and carefully cleaning it.

A method using a cast-in is disclosed in Japanese Patent Publication No. Sho 51-4
It is as described in 1971. This method is a method used when casting an engine rotor, and a casting material having a melting point equal to or higher than the melting point of a casting material is used as a core material.

[0007]

In the casting method of the prior art described above, it is necessary to manufacture a core having a complicated shape for each control valve, and most of the assembly of the core requires relying on manual labor. Therefore, there were problems in terms of productivity and cost.

[0008] Castings are prone to defects such as shrinkage cavities, and the more complicated the interior, the lower the yield. FIG.
Shows this situation. FIG. 17 (a) is a casting for providing the same function as the valve housing described in the above-mentioned Japanese Patent Application Laid-Open No. 5-288204, and shows a cross-sectional portion before machining. FIG. 17B shows an enlarged view of the portion A of the sliding surface of the spool. The broken line in the figure is the target dimension of the land to be finished by machining, and even though defect B can be found by visual observation after casting, defect C and
D cannot be found. If there is a defect B, the valve housing is rejected as a defective product. However, for the defects C and D, machining is performed to the end. The defect C is found in the test after finishing the processing, and the processing cost is also lost. The defect D is not noticed at an early stage even after machining, but causes chipping and fatigue failure during use. As the number of control valves increases, the higher the failure rate becomes, the higher the unit valve cost per unit becomes. Visual inspection and confirmation take a lot of time in such a complicated oil passage, which causes an increase in cost.

In order to newly make a housing by casting, it is necessary to make capital investment in a foundry, and to replace a complicated oil passage with a core shape, it is necessary to manufacture and accumulate know-how on the shape. It is difficult to enter casting production easily. Product development in castings has high initial costs,
It is good for mass production, but there is also a problem that the cost is high for other kinds of small quantities. For the same reason, there is no degree of freedom in design change.

[0010] Next, in the conventional insert molding method described in Japanese Patent Publication No. 51-41971, the insert material must be a material having a higher melting point than the casting material, and the material selection is naturally limited. Come. Especially when casting the sliding part,
Since the material properties and hardness are important parameters that determine the slidability and durability, the inability to select a material was a major problem. Furthermore, since the insert is exposed to the molten metal, it causes a large thermal strain and deformation even if it does not melt. As a result, there is also a problem that when the flanges are cast, the valves and sensors cannot be inserted.

An object of the present invention is to provide a method and structure for producing a casting of a valve housing that can be produced at a high yield and at low cost in view of the above problems.

Another object of the present invention is to provide a method and structure for producing a valve housing casting which can maintain the processing accuracy without melting even a cast-in material having a lower melting point than the casting material in view of the above problems. .

[0013]

Means for Solving the Problems In order to achieve the above object, the present invention has the following features. That is, in a method of manufacturing a valve housing including a flow path through which a fluid flows, a spool that controls the direction of the flow of the fluid, and a pressure adjustment valve and a flow rate adjustment valve that adjusts the pressure and flow rate of the fluid, A spool pipe guide for fitting a spool pipe to be slid therein, a pressure adjustment valve pipe guide for fitting a pressure adjustment valve pipe to which the pressure adjustment valve can be attached, and a flow rate adjustment to which the flow adjustment valve can be attached A flow control valve pipe guide for fitting the valve pipe is separately manufactured, and each pipe guide is combined with the flow path forming core to form a valve housing core. The valve housing body is cast into a mold to form a valve housing body. Wherein each valve guide, corresponding the spool pipe, by securing the pressure regulating valve furan and the flow rate adjusting valve pipe to form said valve housing.

According to the present invention, first, a spool pipe, a pressure adjusting valve pipe, a flow adjusting valve pipe, or a sensor mounting pipe and a spool pipe guide, a pressure adjusting valve pipe guide, or a flow rate which are fitted to these pipes. The adjusting valve pipe guide or the sensor mounting pipe guide is manufactured separately by plastic working such as machining or forging, and finished to the required dimensions.

Of these, each pipe guide is joined to a core for a flow path made of a sand mold to assemble a core for a valve housing. Thereafter, the core for a valve housing is assembled into a matrix to perform casting. After completion, take out the core for the flow path.

Next, a sealing means is provided for each boat so that fluid does not leak between the boats of the aforementioned pipes, and inserted into and fixed to each pipe guide, whereby a valve housing having a cast-in structure can be formed.

Another feature of the present invention is that a fluid flow path, a spool for controlling the flow direction of the fluid, a pressure adjusting valve and a flow rate adjusting valve for adjusting the pressure and flow rate of the fluid in the flow path. A method for manufacturing a valve housing, comprising: a spool pipe for sliding the spool inside; a pressure adjustment valve pipe to which the pressure adjustment valve can be attached; and a flow adjustment valve to which the flow adjustment valve can be attached. Pipe and separately manufactured,
The spool pipe, the pressure adjusting valve, and the flow rate adjusting valve pipe are combined with the flow path forming core to form a valve housing core, and the valve housing core is fitted into a mold and cast. It is in.

Another feature of the present invention is that a valve includes a flow path through which a fluid flows, a spool that controls the direction of the flow of the fluid, a pressure control valve that controls the pressure and flow rate of the fluid, and a flow control valve. In the housing, a spool pipe guide for fitting a spool pipe for sliding the spool inside, a pressure adjustment valve pipe guide for fitting a pressure adjustment valve pipe to which the pressure adjustment valve can be attached, and the flow rate adjustment valve A flow control valve pipe guide for fitting a flow control valve pipe which can be attached thereto is formed integrally with the valve housing body in which the flow path is formed, and corresponds to each of the valve guides of the valve housing body. The spool pipe, the pressure regulating valve franc, and the flow regulating valve pipe In that it is fixed.

Other features of the present invention include a flow path through which a fluid flows, a spool that controls the direction of the flow of the fluid, and a pressure regulating valve and a flow regulating valve that regulate the pressure and flow rate of the fluid. In the valve housing, a spool pipe for sliding the spool inside, a pressure adjusting valve pipe to which the pressure adjusting valve can be attached, and a flow adjusting valve pipe to which the flow adjusting valve can be attached, The present invention is characterized in that the spool, the pressure adjusting valve, and the flow rate adjusting valve corresponding to the respective pipes of the valve housing body are mounted on the respective pipes of the valve housing body.

In the present invention, the spool pipe guide, the pressure adjusting valve pipe guide, the flow rate adjusting valve pipe guide, or the sensor mounting pipe guide is welded to the valve housing by casting for use as a core during casting. . Since the cooling fluid flows in the as-filled pipe guide using the hollow core and the core metal, even if a material having a melting point lower than that of the cast material is used, the entire as-cast material is not melted. Since the pipe guide has a simple cylindrical shape and is constrained by a metal core, thermal deformation is extremely small.

After the casting, the core for the flow path is taken out by washing, and the spool pipe, the pressure adjusting valve pipe, the flow adjusting valve pipe, or the port of the sensor mounting pipe is sealed so as not to communicate, and inserted into the pipe guide. Then, a continuous flow path, a spool sliding portion, a valve port, and a sensor port can be formed. Since the spools, valves, sensors, and the like are covered by independent pipes, defects such as shrinkage cavities generated around the spool pipes in the valve housing and each housing do not pose a problem. Also, if a member having good slidability such as a copper alloy is used for the spool pipe, or if a super hard member is used, the durability will be better than that of the conventional valve housing.

In the present invention, the spool pipe may include:
Alternatively, the pressure adjustment valve pipe, the flow rate adjustment valve pipe guide, or the sensor mounting pipe is welded to the valve housing by casting to be used as a core during casting.

In casting, a cooling fluid flows through a hollow core, so that even if a material having a melting point lower than that of a casting material is used, all of the loose material is not melted. After casting, if the oil passage core is removed by washing, a continuous oil passage, a spool casting portion, a valve port, and a sensor port can be formed.

Defects such as shrinkage cavities generated around the spool pipe in the valve housing and each housing do not become defects such as oil leakage unless there is a defect large enough to penetrate the oil passage. In addition, if the as-cast pipe has been processed in advance, it is not necessary to perform another large processing again, and only the finishing processing is required. Also, if a material having good castability such as a copper alloy is used for the spool pipe, or if a heat-treated super-hard member is used, the durability will be superior to that of the conventional valve housing.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a structure of a control valve housing manufactured according to an embodiment of the present invention. The pressure regulating valve used in this embodiment is a pressure compensating valve, and the flow regulating valve is a make-up valve. In the casting part 1 of the valve housing, a spool pipe guide 14, a pressure compensating valve pipe 22, and a make-up valve guide 32 are inserted. The spool pipe 10, which has been machined to the required dimensions in advance, is inserted into this spool pipe guide 14, and the pressure compensating valve
20 and the make-up valve pipe 30 are also inserted into the respective guides 21 and 32.

The supply of hydraulic oil from the pump 71 to each valve is performed from the oil passage 40. The oil passage 40 is formed by casting inside the casting part 1 and connected to the spool pipe guide 14.

The details of the spool pipe guide 14 are shown in FIG.
Shown in In FIG. 2, 540a and 540b are input ports for hydraulic oil supplied from the oil passage 40, and 543a and 543b are actuators.
The hydraulic oil output boat to 70, 544d and 544c are return ports from the actuator 70, and 541a and 541b are return ports to the tank. 544a and 544b are oil supply boats from the make-up valve 31. The outer peripheral portion of the suburb pipe guide 14 is welded to the casting, and is connected to an oil passage inside the casting. Since the spool pipe 10 to which the O-ring is attached is fitted to the inner peripheral portion of the spool pipe guide 14, the inner peripheral surface 547 has a small surface roughness, and the inner end of the boat end is chamfered. At the end of the spool pipe guide 14, a thread groove for fixing the spool pipe 10 is provided.

Next, the structure of the spool pipe 10 is shown in FIG. The suburb pipe 10 is a pipe in which the spool 11 slides, and in order to control the direction of the hydraulic oil in this part, the inner peripheral part 110 and the land part 120 are preliminarily processed in the inner peripheral part. 140a and 140b are input boats for supplied hydraulic oil, 143a and 143b are output boats for hydraulic oil to the actuator 70, 144d and 144c are return boats from the actuator 70, and 141a and 141b are return boats to tanks. . 144a,
Reference numeral 144b denotes an oil supply boat from the make-up valve 31. The above boats correspond to the same boat of the spool pipe guide 14 described above. After the spool pipe 10 is inserted, the boat position is shifted from the boat position of the spool pipe guide 14 because the spool position is rotationally fixed by the screw portion 121.

Therefore, a spot facing portion 146 is provided at the outer peripheral end of each boat.
This solves the problem caused by the displacement of the spool opening direction from the spool pipe 10 in the boat opening direction. Even if the boats are arranged radially, the same effect as the spot facing portion 146 can be obtained. In order to seal each boat independently, O-ring grooves 147 are provided along the circumference at both ends of each boat seat counterpart 146,
Insert the O-ring 148. As a result, each port of the fitted spool pipe 10 is independently sealed and securely connected to the boat of the spool pipe guide 14.

Returning to FIG. 1, the hydraulic oil supplied from the oil passage 40a is guided via the spool 11 to one of the oil passages 43a which is an output oil passage to the actuator. The oil passage 43a is welded to the pressure compensating valve pipe guide 22.

FIG. 4 shows the details of the pressure compensating valve pipe guide 22. 643a is an input boat for hydraulic oil flowing from the pump 71 through the spool 11, 643b is an output boat for hydraulic oil to the actuator 70, and 644a is a return boat to the spool 11. The outer peripheral portion of the pressure compensating valve pipe guide 22 is welded to the casting, and communicates with the oil passages 43a, 43b, 44a inside the casting. Since the pressure compensating valve pipe to which the O-ring is attached is fitted to the inner peripheral portion of the pressure compensating valve pipe guide 22, the inner peripheral surface 646 must have a small surface roughness. The end of the pressure compensating valve pipe guide 22 is provided with a screw groove for fixing the pressure compensating valve pipe guide.

FIG. 5 shows the structure of the pressure compensating valve pipe 20. In order to fit the pressure compensating valve pipe 20 to the pipe guide 22, the outer peripheral portion is processed in advance with necessary accuracy. Since the pressure compensating valve 21 is directly attached to the pipe 20, the inside diameter is machined to the required accuracy, and a thread 207 for attachment is provided at the end of the pipe.
Also process. In the figure, 243a is an input port of the supplied hydraulic oil, 243b is an output port of the hydraulic oil to the actuator 70,
244a is a return port to the spool. The above ports correspond to the same boat of the pressure compensating valve pipe guide 22 described above. When the pressure compensating valve pipe 20 is rotated and fixed to the threaded portion 206a of the pipe guide 22 by the threaded portion 206, the opening position of the boat shifts. No problem. Even if the spot facing portion 201 is not provided, the same effect can be obtained by arranging the ports radially. In order to seal each boat independently, O-ring grooves 202 and 204 are provided at both ends of the spot facing portion 201 along the circumference, and the O-ring 203 is inserted.
Hydraulic oil input port 243a is O concentric with port
Form a ring groove.

Next, the operation of the control valve housing will be described. In FIG. 1, the pressure compensating valve 21 adjusts the pressure of the working oil in accordance with the pressure detected from the load detection oil passage 45, and adjusts the amount of oil flowing to the actuator 70 through the oil passage 43b. The return oil from the actuator 70 passes through the oil passage 44a from the other oil passage 43b via the inside of the pressure compensating valve 21, and returns from the spool pipe 10 to the tank. When the supply of the operating oil to the actuator is insufficient, the operating oil is supplied from the tank via the make-up valve 31 through the oil passages 41 and 44b. The make-up valve 31 is attached to a make-up valve pipe 30, and the make-up valve pipe 30 is fitted to a make-up valve pipe guide 32 welded to the casting housing 1.

Next, one embodiment of a method of manufacturing the control valve housing having the above-described structure will be described with reference to FIGS. 7 is a sectional view taken along line AA of FIG. 6, FIG. 8 is a sectional view taken along line BB of FIG. 6, FIG. 9 is a sectional view taken along line CC of FIG. 6, and FIG. Note that the control valve housing is generally manufactured as a multi-shaft type in which a plurality of control valve housings are arranged in parallel, and each figure shows a method of assembling the core when the control valve housing is manufactured with a multi-shaft. An example is shown.

As shown by the dots in FIGS. 7 to 9, the hydraulic oil supply core 440 and the oil supply core to the actuator are provided.
443a, 443b, return oil passage core 444a to the tank, load detection oil passage core 450, and makeup oil passage core 440b, 441
Is formed in a conventional sand mold. The oil passages of these cores are appropriately connected to a spool pipe guide 14, a pressure compensating valve pipe guide 22, and a make-up valve pipe guide 32 which have been processed in advance. In this case, the sand type oil path core to be assembled may be connected to the metal pipe guide using an adhesive, or may be fitted by fitting or the like.

The connected core is assembled into a pair of upper and lower mother dies 800 and 810 as shown in FIG. After installation on the master mold, the blower flange of the cooling fan (not shown)
Attach the 450 to the end of the spool pipe guide 14, and close the other end, the pressure compensating valve pipe guide 22, and the make-up valve pipe guide 32 to the discharge flange pipe 45.
1,452,453,454,455 will be installed. In order to feed air into the pressure compensating valve pipe guide 22 and the make-up valve pipe guide 32, a hollow core is used in the part of the oil path core.

In the present embodiment, the oil passage cores 443a and 440b are made hollow, so that the
The cooling air H1 from 450 is supplied to the spool pipe guide 14
Then it is discharged from H2. Similarly, the pressure compensating valve pipe guide 22 can flow from H3 or H4 and can discharge from H7 and H8. Further, in the make-up valve pipe guide 32, it can flow in from H5 or H6 and discharge from H9 and H10.
In this way, the entire cast-in material can be efficiently cooled.

Next, a second manufacturing method of the present invention is shown in FIG. As in the first manufacturing method, oil path cores 440, 443
a, 443b, 444a, 450a, 440b, 441 are formed in a conventional sand mold. Of these, hollow cores are used for the oil passage cores 443a and 440b. Pipe guides 14, 22, 32 are connected to these oil passage cores, and the cores are assembled. Next, the core is inserted into the pipe guide used for the core.

The core metal structure is such that the core metal 610 of the spool melting pipe guide 14 has a cylindrical shape and has screw portions at both ends to which a ventilation flange 650 and a discharge flange 651 can be attached, and communicates with a portion corresponding to the port of the hollow core. It has holes 643a, 643b, 640a, 640b. The core metal 622 of the pressure compensating valve pipe guide 22 has a concave cylindrical shape, has a communication hole 622a for taking in air at the bottom surface, and has a screw portion to which discharge flanges 652 and 653 can be attached at an open end. The core bar 632 of the pipe guide 32 for the make-up valve has a concave cylindrical shape and has a communication hole 622a for taking in air at a position corresponding to the port of the hollow core on the side surface of the cylindrical shape. Has a thread that can be attached. These metal cores have a structure with high rigidity, are manufactured with the final dimensions of the pipe guide, and are made of a material having high thermal conductivity. In this embodiment, high-strength brass is used.

The core into which the metal core has been inserted is assembled into the mother dies 880 and 810. After installation in the master mold, the blower flange 650 of the cooling blower
To the other end of the core bar 610, and the discharge flanges 651, 652, 653, 654, 65 to the opening at the other end and the other core bars 622, 632.
5 is installed. By sending the cooling air at the start of casting, the cooling air can be distributed to all the cast-in materials and can cool the cast-in material. As a result, the cast-in material does not melt to the inside, and the core metal is cooled strongly and does not undergo thermal deformation, so when the heated pipe guide returns to normal temperature, it is restrained by the shape of the core metal and undergoes large deformation. Will not occur. In this embodiment, one cooling air blow port is provided, but the inflow point may be any number of places. Cooling air is kept flowing at least until the casting temperature falls below the casting material melting temperature.

The casting formed by the insert molding method of the valve element can be used satisfactorily even if it has some defects.
The defect E formed around the spool in the defect as shown in FIG. 12 does not affect the pressure leak at all. Conventionally, even if the defect generated in the land portion is minute, it hinders accurate operation or leads to a fatal defect. However, according to the present invention, the defect does not reach the land portion. The pressure compensating valve pipes 20a and 20b and the make-up valve pipe 30
The same can be said for the defect F generated around a and 30b. The defect generated around the oil passage is not a defect that extends between the flow paths as in G2, and there is no functional problem if it is a minute nest such as GI. In addition, since the pilot pipe and the built-in valve are attached to the cast-in material, defects in the attachment portion do not become a problem, and there is an advantage that the number of processing steps after casting is extremely reduced.

As described above, conventional shrinkage cavities and cracks cannot be used even if they are minute, and good or defective cannot be determined until processing is completed due to a defect hidden inside. Up to this point, the loss has occurred. However, if the present invention is used, it can be determined by an initial inspection after completion of casting, such as a penetration defect in the flow path.

In the case of a spool pipe, the sliding characteristics and wear characteristics are problematic. However, in this method, only the spool pipe needs to be changed to another material. For example, the sliding characteristics can be reduced by using a copper alloy for the pipe. Carbon steel hardened and hardened to improve the properties against abrasion and galling can be used. Further, not only a single metal but also a functionally graded material or a composite material can be used.

Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 13 shows the structure of the control valve housing 1 manufactured according to the present invention.
The valve housing includes a spool pipe 10, a pressure adjusting valve pipe 20a, 20b, and a make-up valve pipe 30a,
30b is a cast-in which is taken in the casting.
Supply of hydraulic oil to the valve is performed from an oil passage 40a. The oil passage 40a is connected to the spool pipe 10. A counterbore and a connection hole are formed on the inner diameter side of the spool pipe 10.

First, the structure of the valve housing will be described with reference to FIG. 13 based on the flow of hydraulic oil. The hydraulic oil supplied from the oil passage 40 enters the pressure adjusting valve 21 attached to the pressure adjusting valve pipe 20a through the oil passage 43a by the movement of the spool 11 sliding in the spool pipe 10. The pressure adjusting valve 21 adjusts the pressure in accordance with the pressure detected from the load detecting oil passage 45a, and flows to the actuator 70 through the oil passage 43c. The return from the actuator 70 returns to the tank via the return pipe 41b from the spool pipe 10 to the tank through the oil paths 43d and 44d. When the supply of hydraulic oil to the actuator is insufficient, the hydraulic oil is supplied from the tank oil passages 41a to 44a via the make-up valve 31 installed in the make-up valve pipe 30a.
To move the spool, thread portions are provided at both ends of the spool pipe 10 to fix the pilot pipe 12.

The oil passages are all made of casting, and the spools, pipes on which valves are installed, and the pipes are all formed by machining.
It is connected by melting and welding by casting.

FIG. 1 shows a method of manufacturing the above-mentioned valve housing.
4 to FIG. FIG. 14 shows a mold before casting.
First, the core is for the hydraulic oil supply oil passage 400a, the supply oil passages 430a, 430b, 430c, 430d to the actuator, the return oil passages 440a, 440b, 440c, 440d to the tank, the load detection oil passage 450a, and the make-up. The oil passages 410a and 410b are formed in a conventional sand mold for a core. These oil passages are appropriately connected to a spool pipe 10 pre-processed for pressure adjustment, valve pipes 20a and 20b, and make-up valve pipes 30a and 30b, and assembled.

After that, the connected cores are assembled into the master block 800 (810) as shown in the figure to obtain the state shown in FIG. The ends of the spool pipe 10, the pressure adjusting valve pipes 20a and 20b, and the make-up valve pipes 30a and 30b are open so that their ends are incorporated into a matrix so that hot water does not flow during casting. In FIG. 15, reference numeral 821 denotes a gate, 822 denotes a pool, 823 denotes a runner, 824 denotes a weir, and 825 denotes a deep-fried water.

Next, the connection between the oil path core and the machined component will be described with reference to the drawings. FIG. 16 shows an example in which the oil path cores 430a and 450a are connected to the spool pipe 10. First, each boat of the spool pipe 10 is provided with a spot facing portion 100 as shown in the figure. The spot facing portion is desirably larger than the connected oil passage so that the inside of the oil passage is not pinched by the protrusion of the casting.

Here, oil path cores 430a and 450a are inserted.
Protrusions 431a and 451a are provided on the oil passage core as shown in the figure, and the cores are inserted into respective ports and adhered. By providing the convex portion, the core can be fixed simply by being inserted, so that it is not always necessary to bond the core with an adhesive. However, the core may be bonded as needed.

Since the melting point of the casting is extremely high, in the case of casting conditions in which the cast-in material melts, a cooling fluid such as air is poured in the direction of the arrow shown in FIG. At this time, if the cooling fluid flows in the spool pipe 10 from the direction of H1, it can pass through the inside and escape from the opposite side,
In the pressure adjusting valve pipes 20a and 20b and the make-up valve pipes 30a and 30b, the circulation of the cooling fluid is not performed well because of the dead end. Therefore, the core required for circulation of the cooling fluid is hollow.

In this embodiment, the oil path cores 440a, 440b, 43
The cooling fluid poured from both ends HI of the spool pipe 10 by hollowing 0a, 430b passes through 440a, 440b into the makeup pipe 30a, 30b, through 430a, 430b through the pressure compensation pipe 20a, It flows into 20b, and the spool pipe 10 is also cooled by the cooling fluid. Upon cooling, the cast-in material does not melt into the interior. Also, depending on the shape of the entire casting, the thermal strain of the pipe itself can be reduced. In the present embodiment, the cooling fluid is input from both ends of the spool pipe 10 in order to increase the cooling efficiency. However, the cooling fluid may be input from another pipe, and the inflow point may be one.

It is to be noted that a material containing copper and nickel, which are easily diffused, may be used in order to improve the weldability between the loose material and the casting.

[0054]

According to the present invention, a conventional casting is found to be defective after processing due to an internal defect in the housing, resulting in a loss in processing cost. According to the present invention, such a defect does not occur,
The yield of valve manufacturing can be improved, and individual pipes have a shape that can be easily processed, and mass production is effective, so that there is also an effect of suppressing the overall cost. Further, there is a merit that new functions and characteristics such as spool sliding characteristics and wear characteristics can be added.

Further, in the manufacturing method, since the cast-in material is cast while being cooled by the cooling fluid, the cast-in material is not melted even if the melting point of the cast-in material is lower than that of the casting. Further, in the method of inserting the core metal, the thermal deformation is restrained by the core metal, and almost no thermal deformation occurs. Even when additional processing is required, the processing is as good as the final finishing because the thermal deformation is small, and the production efficiency is good.

[Brief description of the drawings]

FIG. 1 is a structural view of a valve housing according to a first embodiment of the present invention.

FIG. 2 is a detailed structural view of the spool pipe guide of FIG. 1;

FIG. 3 is a detailed structural view of the spool pipe of FIG. 1;

FIG. 4 is a detailed structural view of a pressure compensating valve pipe guide of FIG. 1;

FIG. 5 is a detailed structural view of the pressure compensating valve pipe of FIG. 1;

FIG. 6 is a view showing one embodiment of a mold for manufacturing the control valve housing of FIG. 1;

FIG. 7 is a sectional view taken along the line AA of FIG. 6;

FIG. 8 is a sectional view taken along line BB of FIG. 6;

FIG. 9 is a sectional view taken along the line CC in FIG. 6;

FIG. 10 is an external perspective view of the mold of FIG. 6;

FIG. 11 is a view showing a configuration of a mold for manufacturing a control valve housing according to a second embodiment of the present invention.

FIG. 12 is an explanatory view of a defect generated in a casting process by the method of the present invention.

FIG. 13 is a view showing a structure of a control valve housing manufactured according to another embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of a mold for manufacturing a control valve housing according to a third embodiment of the present invention.

FIG. 15 is an explanatory view of a method of assembling the mold of FIG. 14;

FIG. 16 is a detailed explanatory view of the mold of FIG. 14;

FIG. 17 is an explanatory view of a defect generated in a casting process by a conventional method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Casting part of valve housing, 10 ... Spool pipe, 14 ... Spool pipe guide, 20 ... Pressure compensation valve pipe, 22 ... Pressure compensation valve pipe, 31 ... Makeup valve, 32 ... Makeup valve guide, 40 ... Oil Road,
70 ... actuator

Claims (11)

[Claims] 1. A method of manufacturing a valve housing comprising a flow path of a fluid, a spool for controlling a flow direction of the fluid, a pressure adjusting valve for adjusting a pressure and a flow rate of the fluid, and a flow rate adjusting valve. A spool pipe guide for fitting a spool pipe for sliding the spool inside, a pressure adjustment valve pipe guide for fitting a pressure adjustment valve pipe to which the pressure adjustment valve can be attached, and the flow rate adjustment valve can be attached. And a flow control valve pipe guide for fitting a suitable flow control valve pipe are separately manufactured, and each of the pipe guides is combined with the flow path forming core to constitute a valve housing core. The valve housing core is fitted into a mold to cast and form a valve housing body. A method of manufacturing a valve housing, comprising fixing the spool pipe, the pressure adjusting valve flan and the flow rate adjusting valve pipe respectively corresponding to the valve guides of the main body, thereby forming the valve housing. 2. A flow path for a fluid, a spool for controlling the direction of the flow of the fluid, a pressure regulating valve and a flow regulating valve for regulating the pressure and flow rate of the fluid, and sensing the pressure and flow rate of the fluid. A method for manufacturing a valve housing having a sensor mounting portion, comprising: a spool pipe guide for fitting a spool pipe for sliding the spool inside; and a pressure adjusting valve pipe to which the pressure adjusting valve can be attached. A pressure adjusting valve pipe guide to be fitted, a flow adjusting valve pipe guide to fit a flow adjusting valve pipe to which the flow adjusting valve can be attached, and a sensor mounting pipe guide to fit a sensor mounting pipe are separately provided. And at least one of the pipe guides is used for forming the flow path. In combination with core constitutes the core of the valve housing, said valve housing core, a manufacturing method of the valve housing, which comprises casting forming a valve housing body is fitted into a mold. 3. A valve housing comprising a flow path through which a fluid flows, a spool for controlling the direction of flow of the fluid, a pressure control valve for controlling the pressure and flow rate of the fluid in the flow path, and a flow control valve. In the manufacturing method, a spool pipe for sliding the spool inside,
The pressure adjusting valve pipe to which the pressure adjusting valve can be attached and the flow adjusting valve pipe to which the flow adjusting valve can be attached are separately manufactured, and the spool pipe, the pressure adjusting valve pipe, and the flow rate adjusting. A method of manufacturing a valve housing, comprising forming a valve housing core by combining a valve pipe with the flow path forming core, fitting the valve housing core into a mold, and casting. 4. A flow path through which a fluid flows, a spool for controlling the direction of flow of the fluid, a pressure adjusting valve and a flow rate adjusting valve for adjusting the pressure and flow rate of the fluid in the flow path, A method of manufacturing a valve housing including a sensor mounting portion for sensing a flow rate, a spool pipe for sliding the spool inside,
A pressure adjusting valve pipe to which the pressure adjusting valve can be attached, a flow adjusting valve pipe to which the flow adjusting valve can be attached, and a sensor attaching pipe for fitting the sensor attaching pipe are separately manufactured. A valve housing core is formed by combining at least one of the pipes with the channel forming core, and the valve housing core is fitted into a mold to cast and form a valve housing body. Manufacturing method of a valve housing. 5. A spool, a pressure adjusting valve pipe, a flow rate adjusting valve pipe or a sensor mounting pipe according to any one of claims 1 to 4, wherein lands, port holes and connection screws are set to required dimensions in advance. A method for manufacturing a valve housing, wherein a slot or the like is machined, and the ports are sealed. 6. A method for manufacturing a valve housing according to claim 5, wherein the outer peripheral portion of the port hole which has been previously machined is cut along the circumference of the pipe or the port is formed radially. 7. A method for manufacturing a valve housing according to claim 3, wherein the pipe used for said core is subjected to necessary machining in advance. 8. The spool according to claim 1, wherein the material of the spool pipe used for the core is any one of carbon steel, nickel steel, copper alloy, and a composite material thereof. Manufacturing method of valve housing. 9. A valve housing having a flow path for fluid, a spool for controlling the direction of flow of the fluid, a pressure regulating valve for regulating the pressure and flow rate of the fluid, and a flow regulating valve. A spool pipe guide for fitting a spool pipe to be slid therein, a pressure adjustment valve pipe guide for fitting a pressure adjustment valve pipe to which the pressure adjustment valve can be attached, and a flow rate adjustment to which the flow adjustment valve can be attached A flow control valve pipe guide for fitting a valve pipe is integrally formed with the valve housing body in which the flow path is formed. The spool pipes respectively corresponding to the pipe guides of the valve housing body, Check that the pressure adjustment valve pipe and the flow adjustment valve pipe are fixed. Valve housing according to claim. 10. A valve housing, comprising: a flow path through which a fluid flows; a spool that controls the direction of the flow of the fluid; and a pressure adjustment valve and a flow rate adjustment valve that adjust the pressure and flow rate of the fluid. A pipe for the spool to slide inside,
A pressure adjusting valve pipe to which the pressure adjusting valve can be attached, and a flow adjusting valve pipe to which the flow adjusting valve can be attached are integrally formed with a valve housing body in which the flow path is formed; A valve housing, wherein a corresponding one of the spool, the pressure adjustment valve, and the flow rate adjustment valve is mounted on each of the pipes of the housing body. 11. The valve housing according to claim 9, wherein a material of the spool pipe is one of carbon steel, nickel steel, a copper alloy, and a composite material thereof. Valve housing.