JPH10131913A - Cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized cylinder device capable of extracting a rod while rotated, applied to a set/extraction device for a core pin in die casting. SOLUTION: In a position opposed to an axial center of a rod 4 in a head cover 3, a screw bar 6 formed with an external thread 6a of large lead angle (45 deg. to 87 deg.) is fixedly vertically provided, in a piston 5, an axial direction hole 7 internally fitting the screw bar 6 from a rear end surface is left as formed, also in this rear end surface, a guide plate 8 formed with an internal thread 8a screwed to the screw bar 6 is fixedly mounted. Each screw 6a, 8a is formed so as to constitute a space serving as a fluid flow path mutually between screw surfaces in a screwed condition thereof. By oil pressure control from ports P1, P2, a piston rod 5, 4 is moved, but based on the screwing relation, the rod 4 always makes a stroke accompanied with rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder device, for example, which is applied to the setting and pulling out of a core pin of a die-casting die. It relates to the structure of possible small cylinders.

[0002]

2. Description of the Related Art Conventionally, a hydraulic cylinder is often used for setting and extracting a core of a die casting mold. In this case, a description will be given with reference to FIG. 10 which is the simplest example. First, the movable mold 101 having the core pin 101a attached thereto is described.
Is fitted to the fixed mold 102 side by the operation of the hydraulic cylinder, and the mold is clamped. The molten metal is poured from the gate 104 into the cavity 103 formed in this state. Then, when the molten metal is solidified, the movable mold 101 is pulled up, and the fixed mold 102 is opened to obtain a product.

However, since the molten metal is cooled and shrunk and solidified, when the movable die 101 is pulled up and the core pin 101a is pulled out of the product, galling or seizure occurs between the core pin 101a and the product side. Cheap. Therefore, in general, the core pin 101a is provided with a draft α as shown in FIG. 10 so as to prevent the above-mentioned problem, but the hole formed by the core pin 101a is fitted therein. In many cases, a highly accurate hole diameter is required for the hammer-eye tolerance in relation to the member, and even if galling or seizure can be prevented as described above, conversely, machining is required after molding, and naturally the product Cost increases.

On the other hand, in order to suppress galling and seizure which may occur even if the draft angle α is provided, and to reduce the force when pulling out the core pin 101a, the core pin 101a is pulled out while rotating. A device has also been proposed.
1-167255). The apparatus has a configuration as shown in FIG. 11 and includes a hydraulic mechanism 10 for driving a core pin 101a inserted into a product part (corresponding to a cavity) 103 of a die casting mold 102.
5, a connecting sleeve 108 having an inclined guide groove 107 is fixed to an end of a piston rod 106 of the hydraulic mechanism 105, and one end is fixed to the core pin 101a in the connecting sleeve 108. The other end 109a of the connecting rod 109 is slidably accommodated, and a connecting pin 110 slidably fixed in the guide groove 107 of the connecting sleeve 108 is fixed to the other end 109a of the connecting rod 109. When driving the connection sleeve 108 in a direction in which the core pin 101a is pulled out from the product part 103, the connection pin 110 slides in the guide groove 107 of the connection sleeve 108, and the connection rod 10
9. A die casting die casting apparatus characterized in that the core pin 101a is rotated via a pin 9.

Further, as a technique directly related to the problem of galling and seizure, a fluid passage for temperature adjustment is formed in a mold to control the surface temperature of the core pin and the peripheral temperature of the cavity. A die casting method has also been proposed in which the core pin is pulled out immediately after opening the mold to reduce the draft α within a range of about 0 to 20 minutes (JP-A-8-117958).

[0006]

By the way, when the applicant of the present invention carried out an experiment of removing a core pin in a die casting process under various conditions, the molten metal became semi-solid in the cavity. By rotating the core pin at a predetermined timing and pulling it out, or by pulling it out while rotating, it is possible to form a hole with extremely high accuracy even if the core pin is not given the draft α as described above. It turned out to be.

In this case, the die casting die casting apparatus disclosed in the above-mentioned Japanese Utility Model Application Laid-Open No. 61-167255 realizes the operation of pulling out while rotating the core pin. Is considered to be effective. However, FIG.
As shown in FIG. 1, the apparatus includes a connecting sleeve 108 having an inclined guide groove 107 and a connecting rod 10 having a connecting pin 110.
The hydraulic mechanism 105 is connected to the core pin 101a via the connecting mechanism consisting of
, The size of the device increases in the axial direction, and it is impossible to apply the device to a device that obtains a product having a complicated shape using a large number of core pins. In addition, since the connecting pin 110 slides in the inclined guide groove 107 to apply a rotational driving force to the core pin 101a, it is difficult to accurately fix the core pin 101a to a fixed position and to pull out the core pin 101a. In this case, if there is looseness in the connecting portion, a bending moment acts on the connecting rod 109, and as a result, the movable mold 101 and the fixed mold 102
This may cause galling between them and may cause cracks and the like in the molded product. Incidentally, Japanese Utility Model Application No. 61-167255 (Fig. 11)
Although not disclosed, a means for restraining the rotation of the piston rod 106 on the hydraulic mechanism 101 side is required.

Accordingly, the present invention provides a cylinder device which can be configured to be extremely small, can fix and set the core pin at a predetermined position with high accuracy, and can simultaneously perform the pulling out and the rotation with a stable operation. It was created for the purpose of enabling high-precision hole forming without the need for additional processing while using a core pin that does not give a draft α in die casting.

[0009]

A first invention is a cylinder device having a basic structure of a single rod cylinder,
At the position facing the piston rod axial center on the cylinder chamber side of the head cover, a guide rod longer than the stroke length of the piston rod and having a male screw with a large lead angle formed on the outer periphery is erected and fixed. The piston rod comprises a main body and a guide plate abutted and fixed to the rear end face of the piston, and the main body has a male screw of the threaded rod centered on the axis of the rod from the rear end face side. An axial hole having an inner diameter larger than the thread diameter of the screw and deeper than a length obtained by subtracting the thickness of the guide plate from the length of the screw rod is formed, and the guide plate has a concentric position with the axial hole. And a female screw hole formed to be screwed into the screw rod with a gap serving as a fluid flow path interposed therebetween.

In the cylinder device of the present invention, the piston rod is driven by the supply control of the fluid pressure to the port in the same manner as a normal single rod cylinder, but the male screw on the guide rod side and the female screw on the guide plate side are screwed. Since the mating relationship is based on a large lead angle, the piston rod moves with rotation only by supplying a small driving fluid pressure. In this case, when the piston rod moves, the inside of the axial hole of the main body tends to be decompressed or pressurized, but the male screw on the guide rod side and the female screw on the guide plate side have a gap that forms a fluid flow path. And the fluid inside the axial hole flows through the gap with the cylinder chamber on the rear side of the piston rod, so that little load is applied to the driving of the piston rod. In addition, when applied as a core removing cylinder device, it is sufficient to rotate the core by a small angle at the time of pulling out, so that the lead angle of the screw is 45 ° or more and less than 87 °. The setting can be made in an extremely large range, and the movement of the piston rod with rotation can be realized at a pressure substantially equal to the fluid pressure supplied to the normal cylinder device.

A second aspect of the present invention is a cylinder device having a basic structure of a single rod cylinder, wherein a rod cover is provided with a rod cover in a certain section on the cylinder chamber side around the axis of a rod through hole. A large female screw hole is formed, while the piston rod has a male screw portion which is screwed into the front end surface of the piston with a gap serving as a fluid flow path interposed between the female screw hole of the rod cover and the female screw hole. Configure and
From the rear end side, the piston
An axial hole deeper than the stroke length of the rod is formed, and a small protrusion is projected on the inner peripheral surface of the axial hole.The head cover has a position corresponding to the axis of the piston rod on the cylinder chamber side, The piston / rod is inserted and inserted into the axial hole of the piston / rod with a gap serving as a fluid flow path interposed therebetween, and guided in the axial direction while the small projection of the piston / rod is internally fitted on the outer peripheral surface. The present invention relates to a cylinder device wherein a guide rod having a guide groove for establishing a screwing relationship between a male screw portion of a rod and a female screw hole of the rod cover is erected and fixed.

According to the cylinder device of the present invention, the rod moves while the rod is rotated in the entire stroke section in the first invention, whereas the retracting step is performed from the final fixed section in the rod protruding step and the longest protruding state. It has a configuration for causing the piston rod to move with rotation only in a certain section when shifting to. In the rod protruding step, the piston rod advances forward with its small protrusion guided by the guide groove of the guide rod, and the rod is protruded without rotation. Immediately before the male thread of the piston cover fits into the female thread of the rod cover, guide the small protrusions of the piston and rod so that the peaks and valleys of both threads correspond, and screw the two threads together in the last fixed section of the process. Establish a relationship. Therefore, when the piston rod is further moved forward after the threading relationship is established, the rod is projected forward while rotating in the fixed section. On the other hand, in the retraction process from the longest protruding state, since the screwing relationship is established only in the certain section, when the piston rod is moved backward, the rod is rotated while rotating in the reverse direction in the section in the section. It is. Also, in the retraction step, the small projection of the piston rod is guided by the guide groove of the guide rod, and when the retraction with rotation in the certain section is completed, the piston rod moves without rotation and the retraction step. Complete. By the way, when the piston rod moves, the inside of the axial hole of the piston rod tends to be decompressed or pressurized, and in the moving state with the screwing relation in the certain section, the female screw of the rod cover is moved. Although the inside of the hole tends to be pressurized or depressurized, a gap is formed between the axial hole of the piston rod and the outer peripheral surface of the guide rod for the former, and the same as the first invention for the latter. Since a gap is formed between the female screw on the rod cover side and the male screw on the piston / rod side, the gap serves as a fluid flow path to cancel the above-described pressure reduction or pressurization. In addition, the lead angle of the screw is 45 ° or more and 87 ° or more.
The fact that it can be set in an extremely large range, such as less than, is the same as in the first invention.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS. << Embodiment 1 >> First, FIG. 1 is a sectional view of a cylinder device according to this embodiment. In the figure, 1 is a rod cover, 2 is a cylinder tube, 3 is a head cover, 4 is a rod, 5 is a piston, P1 and P2 are ports, and the basic structure is the same as a normal single rod cylinder device. The entire cylinder device is mounted at a desired position using a mounting screw hole formed on the rear end surface of the head cover 3 and, similarly to a normal cylinder device, is mounted with an O-ring or packing. A seal mechanism is provided in place.

This cylinder device has the following features. (1) A guide rod 6 having an external thread 6a formed on its outer periphery is erected and fixed at a position exactly corresponding to the axis of the rod 4 on the cylinder chamber side of the head cover 3. (2) An axial hole 7 having an inner diameter larger than the ridge diameter of the external thread 6a of the guide rod 6 is formed from the rear end face side of the piston 5 around the axis of the rod 4. (3) A guide plate 8 in which a female screw hole 8a to be screwed with the male screw 6a of the guide rod 6 is accurately positioned and abutted on the rear end surface of the piston 5. More specifically, the guide rod 6 is longer than the stroke length of the piston rods 5 and 4, and the axial hole 7 is formed deeper than the total length of the guide rod 6 minus the thickness of the guide plate 8, The entire stroke movement of the piston 5 is ensured, and the threaded relationship between the male screw 6a of the guide rod 6 and the female screw hole 8a of the guide plate 8 is always ensured during the stroke.

In this embodiment, the male screw 6a on the guide rod 6 and the female screw hole 8a on the guide plate 8 are parallel screws, and each screw has a very large lead angle of 82 °. θ. When the threaded state of each screw is viewed in a cross-sectional view, as shown in FIG. 2, the teeth of the external thread 6a on the guide rod 6 side and the teeth of the female screw hole 8a on the guide plate 8 side are spline-coupled. And a gap 9 is formed between the crest of the male screw 6a and the trough on the side of the female screw hole 8a. In this embodiment, the number of teeth is 12, and the module has an engagement relationship of 1.25.

In the above configuration, the rod 4 shown in FIG.
With port P1 in drain state
When the pressure oil is supplied to P2, the piston rods 5 and 4 move forward due to the pressurization of the rear cylinder chamber 10 and the protruding process of the rod 4 is started, but the external thread 6 of the guide rod 6 is started.
Based on the screwing relationship between a and the female screw hole 8a of the guide plate 8, the piston 5 is forcibly rotated while moving forward, and the rod 4 is protruded with rotation.

FIG. 3 shows the stage where the piston rods 5, 4 are in the middle of the stroke. Here, when the piston 5 and the guide plate 8 move forward in the step of projecting the rod 4, the guide rod 6 is pulled out from the inside of the axial hole 7 formed in the piston 5. The inside of the direction hole 7 is decompressed, and a load tends to be applied to the movement of the piston 5. However, as shown in FIG. 2, a gap 9 is formed between each crest of the male screw 6a on the guide rod 6 side and each crest of the screw in the female screw hole 8a on the guide plate 8 side. The pressure oil in the cylinder chamber 10 always flows into the inside of the axial hole 7 through each of the gaps 9 to cancel the above-described tendency to reduce the pressure. Therefore, each screw has a screwing relationship at a large lead angle of 82 °, and the clearance 9 described above makes the rear cylinder chamber 1
Due to the fact that the flow path is formed inside the 0 and the axial hole 7, the load generated by the rotation and movement of the piston rods 5, 4 is almost only the external load on the rod 4, and the normal cylinder device The protruding step can be executed with a pressure substantially equal to the pressure.

The projecting step of the rod 4 is completed when the front end face of the piston 5 comes into contact with the rod cover 1. However, as described above, the guide rod 6 is configured to be longer than the stroke length of the piston rods 5, 4. As a result, the rod 4 is forcibly rotated over the entire length of the protruding process, and the screwing relationship between the male screw 6a of the guide rod 6 and the female screw hole 8a of the guide plate 8 is maintained even in the completed state of the process. .

On the other hand, the retracting step of the rod 4 is performed at the port P2
Is performed by setting the port P1 to the drain state and switching the port P1 to the pressure oil supply state. In this case, the piston rods 5, 4 move rearward due to the pressurization of the front cylinder chamber 11, but also move while being forcibly rotated based on the screwing relationship. However, since the piston rods 5 and 4 are moved backward, the piston rods 5 and 4 move while rotating in the direction opposite to the above-described protruding step.

In the pulling-in step, the guide rod
6 is inserted into the axial hole 7 of the piston 5, so that the inside of the axial hole 7 is pressurized and a load tends to be applied to the movement of the piston 5, but the oil inside the axial hole 7 Flows into the rear cylinder chamber 10 of the drain pressure through each gap 9 formed between the thread of the external thread 6a on the guide rod 6 side and the thread root of the internal thread hole 8a on the guide plate 8 side. The tendency to pressurize is canceled and the piston rod
The load applied to the rotation and movement of 5, 4 is almost only the external load on the rod 4.

As described above, the cylinder device of this embodiment enables the rod 4 to reciprocate while forcibly rotating in the protruding step and the retracting step of the rod 4, and the forced rotation mechanism is provided inside. This is due to the threaded relationship between the guide rod 6 and the guide plate 8 and is almost the same in appearance as a normal single rod cylinder. Therefore, it can be configured as a very small cylinder device, and the guide rod 6 is erected and fixed to the head cover 3 of a normal single rod cylinder device, the axial hole 7 is formed in the piston 5 and the guide plate 8 is formed on the rear end face. Since the function can be changed only by mounting, it can be realized by a simple design change without changing the overall size of the conventional general-purpose cylinder device.

By the way, it is assumed that the cylinder device of this embodiment is applied to a coreless application. Therefore, a large rotation angle is not required for the rod 4, and the lead angle θ between the male screw 6a of the guide rod 6 and the female screw hole 8a of the guide plate 8 is set at 82 °, so that the rod 4 can be protruded / retracted in the process. An angle of rotation of 8 ° is provided. However, even if the lead angle θ is selected as small as about 45 °,
Due to the screwing relationship of the screws, no significant load is applied to the piston rods 5, 4. In FIG. 2, a gap is drawn between the teeth of the male screw 6a on the guide rod 6 side and the side walls of the teeth of the female screw hole 8a on the guide plate 8 side. It is also possible to make the rotation of the piston rods 5 and 4 highly accurate by making the angle as small as possible, for example, by setting the above-mentioned lead angle θ to 87 ° and turning a small angle during the stroke. You can also move it. Note that the range of the lead angle θ may be set according to the use of the cylinder device or the stroke length, and may be set to 45 ° or less as long as the rotation function is not hindered.
87 ° or more and 90 when a very small rotation angle is sufficient
° may be selected. Further, in the present embodiment, the screw
Although 6a and 8a are configured as parallel threads, if the rotation torque required for the rod 4 is not so large, it may be configured as a tapered thread.

Second Embodiment In the cylinder device of the first embodiment, the rod 4 is forcibly rotated over the entire stroke length of the protruding step and the retracting step of the rod 4. However, in the cylinder device applied to the core removal application, it is sufficient to rotate the rod only in a small section when the core is pulled out, and there is no need to rotate the rod over the entire stroke length. In the cylinder device of the first embodiment, since the screws of the guide rod 6 and the guide plate 8 are always screwed together, they can be ignored when the lead angle θ is small.
When it gets bigger, the piston rod
The load exerted on the movement of 5, 4 increases, and the supply pressure of the pressurized oil must be increased accordingly. Therefore, in this embodiment, a cylinder device capable of rotating the rod only for a certain section from the longest protruding position of the rod and performing only movement without rotation in other sections similarly to a normal cylinder apparatus is provided. Realize.

FIG. 4 is a sectional view of the cylinder device according to this embodiment. In the figure, 21 is a rod cover,
22 is a cylinder tube, 23 is a head cover, 24 is a rod, 25 is a piston, 26 is a mounting flange, P21, P22
Is a port, and its basic structure is the same as that of the normal single rod cylinder device as in the first embodiment. However, in this cylinder device, the stroke length is longer than in the first embodiment, and the overall length of the device is longer.

The features of this cylinder device are as follows. (1) A counterbore-shaped screw hole is formed on the cylinder chamber side of the rod cover 21 at a position corresponding to the axis of the rod 24, and the outer periphery is screwed into the screw hole and the screw is formed. A rotation forcing plate 27 which is an annular body having the same thickness as the depth of the hole and in which a female screw 27a having a large lead angle θ is formed on the inner peripheral surface is screwed and fixed in the screw hole. ing.
The thread diameter of the female screw 27a of the rotation forcing plate 27 is
Larger than the outer diameter of (2) A screwing sleeve 28 having an external thread 28a fitted on the rod 24 and formed on the outer peripheral surface thereof with an internal thread 27a of the rotation forcing plate 27 is fixed to the front side of the piston 25. ing. (3) The rod 24 penetrates the piston 25 to its rear end face, but an axial hole 29 is formed from the rear end face of the rod 24 to the center of its axis and deeper than the stroke length of the piston rod 25, 24. . (4) The head cover 23 has an outer diameter smaller than the inner diameter of the axial hole 29 formed in the rod 24 at a position corresponding to the center axis of the rod 24, and corresponds to the stroke length of the piston rod 25, 24. A guide rod 30 having a length is erected and fixed. A guide groove 31 having a constant width is formed in the outer peripheral surface of the guide rod 30 along the axial direction. The guide groove 31 has a thickness corresponding to the thickness of the rotation forcing plate 27 at the tip end of the guide rod 30. Is an open angle mode in which the width gradually increases in one circumferential direction in the section corresponding to. (5) A screw hole penetrating from the rear side position of the outer peripheral surface of the piston 25 to the axial hole 29 formed in the rod 24 in the direction of the central axis of the rod 24 is formed. A flat-point stop screwed into the guide groove 32 formed on the guide rod 30 by screwing the rod-end set screw 32 formed as the guide pin 32a into the guide groove 31 formed on the guide rod 30 from the rear end face of the piston 25. It is fixed with screws 33.

The above features will be described in more detail.
5A is a cross-sectional view and FIG.
And (B), the female screw 27a on the inner peripheral side is formed as a parallel screw, and the lead angle θ is set to 60 ° as shown in (C) of FIG. On the other hand, FIGS. 6A and 6B are a front view and a cross-sectional view of the screwing sleeve 28 shown in FIG. 6A, respectively.
Are formed as parallel screws corresponding to the female screw 27a of FIG. 1, and as shown in FIG.
Is set to However, male screw 28a of screwing sleeve 28
The number of teeth and the module correspond to the female screw 27a of the rotation forcing plate 27.
Is smaller than the root diameter of the female screw 27a, and a gap is formed between the peak surface and the root surface in the screwed state of both. Further, side and front views of the guide rod 30 and a plan view and a cross-sectional view thereof as viewed from the formation side of the guide groove 31 are shown in FIGS. 7A, 7B, 7C and 7D, respectively. . As is clear from the figure, the guide groove 31 is formed linearly in the axial direction, but the width gradually increases in one circumferential direction in the section S corresponding to the thickness of the rotation forcing plate 27 at the tip end. The opening angle γ is determined by the screwing relationship between the female screw 27a of the rotation forcing plate 27 and the male screw 28a of the screwing sleeve 28. Specifically, the distance that the male screw 28a moves in the screwed state is represented by Δx, and the rotational distance in the circumferential direction of the male screw 28a corresponding to the movement distance Δx is represented by Δy.
Is given by tanγ = Δy / Δx.
However, it is not necessary to exactly satisfy the above condition,
There is no problem even if γ is set to be larger than the above angle.

Next, the operation of the cylinder device according to this embodiment will be described based on the above configuration. First, in the retracted state of the rod 24 shown in FIG. 4, when the port P21 is set to the drain state and the port P22 is set to the pressure oil supply state, the piston rods 25 and 24 move forward by the pressurization of the rear cylinder chamber 34, 24 ejection processes are started. In this case, the guide pin 32 on the piston 25 side is fitted in the guide groove 31 of the guide rod 30, but since the guide groove 31 is formed linearly in the axial direction, as shown in FIG.・
The rods 25 and 24 move forward without rotating, similarly to a normal cylinder device. However, in this cylinder device, since the guide rod 30 is inserted into the axial hole 29 of the rod 24, the axial hole is
The interior of 29 will be depressurized. However, as described in the above (4), the outer diameter of the guide rod 30 is smaller than the inner diameter of the axial hole 29 of the rod 24, and a constant gap 35 is formed between them, The pressurized oil in the rear cylinder chamber 34 in the pressurized state flows into the axial hole 29 through the gap 35 to cancel the decompression tendency. Therefore, no extra load is generated as the piston rods 25, 24 advance, and the supply of pressure oil to the port P22 causes the rod 2 to move.
4 is quickly extruded.

When the above-described protruding process proceeds, the male screw 28a of the screwing sleeve 28 provided on the front surface of the piston 25 is replaced with the female screw 27a of the rotation forcing plate 27 provided on the rod cover 21.
To a state where it fits into By the way, until the fitting start state, the guide groove 31 of the guide rod 30 guides the guide pin 32a of the piston 25, but the guide rod 30 moves the circumferential position of the guide groove 31 at the time of the fitting start. The thread of the male screw 28a on the screwing sleeve 28 side and the female screw 27a of the rotation forcing plate 27
The valleys are set up and fixed so that they match.
Therefore, the male screw 28a on the screwing sleeve 28 side is
The piston rods 25 and 24 move forward in a state where the screwing is surely inserted into the female screw 27a. As shown in FIGS. 5 and 6 (C), on the screwing start side of the female screw 27a of the rotation forcing plate 27 and the male screw 28a of the screwing sleeve 28, the side wall of each parallel screw comes first. It is formed in a thin tapered shape, and the initial screwing of both is smoothly performed.

After the above screwing relationship is established, the piston
When the rods 25 and 24 are advanced, the state shown in FIG. 9 is obtained. On the basis of the screwing relationship, a rotational force acts on the piston rods 25 and 24 and a section corresponding to the thickness of the rotation forcing plate 27 is formed. In this case, it is forcibly rotated while moving forward. By the way, in that case, the female screw 27 of the rotation forcing plate 27
The inside of a is pressurized by the screwing of the screwing sleeve 28, but as described above, the male screw of the screwing sleeve 28
The crest diameter of 28a is smaller than the root diameter of the female screw 27a of the rotation forcing plate 27, and since a gap 36 is formed between the crest surface and the root surface, the inside of the female screw 27a of the rotation forcing plate 27 is formed. Oil flows into the front cylinder chamber through the gap 36 to cancel the pressurized state. Therefore, even in this protruding section, no extra load is applied to the movement of the piston rods 25, 24, and the rod 24 is protruded smoothly with rotation. In this embodiment, the lead angle θ between the male screw 28a of the screwing sleeve 28 and the female screw 27a of the rotation forcing plate 27 is set to 60.
Due to the setting in degrees, the rod 24 rotates by 30 degrees in the protruding section.

When the piston rods 25 and 24 rotate, the guide pin 32a naturally rotates. In this case, if the guide pin 32a is in the straight section of the guide groove 31 of the guide rod 30, its rotation is hindered. However, as shown in FIG. Dynamic force plate 27
In the section in which the female screw 27a and the male screw 28a of the screwing sleeve 28 are screwed), the width is gradually increased in one circumferential direction at the opening angle γ. Therefore, the guide pin 32 a rotates in the circumferential direction at the open angle portion, and is not restrained by the guide groove 31. In the above protruding step, the front surface of the piston 25 is moved from the surface of the rod cover 21 on the front cylinder chamber side (the rotation force plate 27).
(The front cylinder chamber side surface of the rod cover 21) at that time, at which point the front end surface of the screwing sleeve 28 is located just before the surface of the rod cover 21 formed inside the female screw 27a of the rotation forcing plate 27. Located in.

On the other hand, the step of retracting the rod 24
It is executed immediately by simply switching P22 to the drain state and port P21 to the pressure oil supply state. First, in the retraction process, the front cylinder chamber 37 is pressurized, and the piston rods 25 and 24 start to retract.
27a and the external thread 28a of the screwing sleeve 28 are screwed. Therefore, the piston rods 25 and 24 are retracted while rotating in the direction opposite to the above-described protruding step.

In the process, contrary to the above-described projecting step, the inside of the female screw 27a of the rotation forcing plate 27 is depressurized by the retreat of the screwing sleeve 28, and is formed on the rod 24. The inside of the axial hole 29 is in a pressurized state. However, in this case, too,
A gap 36 is formed between the crest surface of 28a and the root surface of the female screw 27a of the rotation forcing plate 27, and between the outer peripheral surface of the guide rod 30 and the inner peripheral surface of the axial hole 29 of the rod 24. Since the gap 35 is secured between the gaps 36 and 35, the gaps 36 and 35 serve as oil flow paths, and the above-described reduced pressure state and pressurized state are canceled, and an extra load is applied to the movement of the piston rods 25 and 24. It does not take. In addition, gap 3
The function as the flow path of No. 5 is effective over the entire length of the subsequent drawing process.

As the above-described drawing step proceeds, the male screw 28a of the screwing sleeve 28 is released from the screwing relationship with the female screw 27a of the rotation forcing plate 27. In this case, the guide pin 32a of the piston 25 rotates the open angle portion of the guide groove 31 formed in the fixed section S of the guide rod 30, and automatically returns to the entrance of the linear portion. However, as shown in FIGS. 5 and 6C, if the screwing start portion of the female screw 27a and the male screw 28a is formed in a tapered shape, the screwing sleeve 28 has a slight degree of freedom of rotation. Occurs, and it may not be possible to guarantee that the guide pin 32a returns to the entrance of the linear portion of the guide groove 31. Here, the opening angle γ given to the opening portion of the guide groove 31 as described above effectively functions as a countermeasure, and even if the piston rods 25, 24 rotate indefinitely at the stage of releasing the screwing relationship. The guide pin 32a is surely guided to the linear portion of the guide groove 31.

Therefore, when the screwing sleeve 28 is released from the screwing relationship with the rotation forcing plate 27, the guide pin 32a smoothly fits into the linear portion of the guide groove 31 and runs. 4, the piston rods 25 and 24 are retracted without rotating by continuing the pressurized state of the front cylinder chamber 37, and the piston 25 comes to the initial state of FIG. The pull-in process is completed.

As a result of the above operation, according to the cylinder device of this embodiment, in the protruding step, the rod 24 is protruded in a non-rotating state in the initial long section in the same manner as in the ordinary cylinder apparatus, and only in the final short section. In the retracting process, it is possible to execute the retracting with rotation only in the initial short section, and to perform the retracting in the non-rotating state in the subsequent long section. And the operation is most suitable for the drive control of the core pin in die casting, and the core connected to the rod 24 is accurately set to a predetermined position of the mold, and the core is set in a state where the molten metal is solidified or semi-solidified. The core can be pulled out while being rotated, and the core can be quickly separated without being rotated after the drawing.

In particular, when the rod is rotated in the entire stroke section as in the cylinder device of the first embodiment, if the rod is applied to a core having a large rotational inertia, the connecting portion between the rod and the core or the cylinder is stopped when the rotation is stopped. The cylinder itself of this embodiment applies a rotational force to the core only in the set / pull-out section, and the other sections cause a failure due to the occurrence of shock torsion in the apparatus itself. Since no rotation is applied, the problem caused by the rotational inertia as described above can be solved, and a system that operates stably and has excellent durability can be configured. Further, the cylinder device of this embodiment is
Since all of the mechanisms for performing the above operations are incorporated inside, the device can be configured to be extremely small.

[0037]

According to the cylinder device of the present invention having the above-described structure, the following effects can be obtained. The invention of claim 1 provides a small-sized cylinder device capable of executing a protruding / retracting process while imparting rotation to a rod while having the structure of a normal single-rod cylinder, and is particularly used in die casting. When applied to the setting and drawing of a core pin and a mold having axial symmetry, the core can be pulled out while rotating the core etc. in the semi-hardened state of the molten metal. It is possible to form accurate holes and the like. In addition, since all the mechanisms for realizing the rotation and movement of the rod are built into the cylinder, it can be configured as a very small cylinder device, and can be easily incorporated into a die casting device having many molded parts. . Further, the cylinder device according to the present invention can be realized only by making a simple design change to the conventional general-purpose cylinder device, and has an advantage that parts of the general-purpose cylinder device can be used as they are. The invention according to claim 3 realizes an operation in which the rod is rotated only in the final fixed section of the protruding step and the fixed predetermined section in the initial stage of the retraction step, and the rod is not rotated in other sections. A cylinder device more suitable than the invention of claim 1 is provided as a drawing device. The invention of claim 4 is the invention of claim 3
The invention realizes a configuration in which the rotation / non-rotation transition operation of the rod in the invention according to the invention is executed reliably and smoothly. The invention according to claim 2 and claim 5 is based on the assumption that the cylinder device according to claim 1, claim 3 or claim 4 is applied as a core removing cylinder. It does not generate much extra load and provides a range of lead angles for the screwing mechanism when operating with a small pivot angle.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder device according to a first embodiment.

FIG. 2 is a cross-sectional view showing a screwed state between a male screw on a guide rod side and a female screw hole on a guide plate side.

FIG. 3 is a sectional view of the cylinder device in a state where a piston rod is moved.

FIG. 4 is a sectional view of a cylinder device according to a second embodiment.

FIG. 5 is a sectional view (A) and a front view (B) of the rotation forcing plate, and a detailed view (C) of the female screw portion.

FIGS. 6A and 6B are a front view (A), a sectional view (B), and a detailed view (C) of a male screw portion of the screwing sleeve 28. FIGS.

FIG. 7 is a side view (A) and a front view (B) of the guide rod, a plan view (C) as viewed from the side where the guide groove is formed, and a cross-sectional view thereof (as viewed from arrow XX) (D).
It is.

FIG. 8 is a cross-sectional view of the cylinder device in which a piston rod is in a non-rotating and moving state.

FIG. 9 is a partial cross-sectional view of the cylinder device when the piston / rod is in a rotating / moving state.

FIG. 10 is a cross-sectional view showing a case where a cavity is formed by clamping a movable mold having a core pin with respect to a fixed mold in die casting.

FIG. 11 is a schematic configuration diagram of a conventional device for pulling out a core pin while rotating it (Japanese Utility Model Application Laid-Open No. 61-167255).

[Explanation of symbols]

1 ... Rod cover, 2 ... Cylinder tube, 3 ... Head cover, 4 ... Rod, 5 ... Piston, 6 ... Screw rod, 6a ... Male screw, 7 ... Axial hole, 8 ... Guide plate, 8a ... Female screw hole, 9 ... clearance, 10 ... rear cylinder chamber, 11 ... front cylinder chamber, 21 ... rod cover, 22 ... cylinder tube, 23 ... head cover, 24 ... rod, 25 ... piston, 26 ... mounting flange, 27 ... rotation forcing plate , 27a ... female screw, 28 ... screwing sleeve, 28a ... male screw, 29 ... axial hole, 30 ... guide rod, 31 ...
Guide groove, 32… Bar set screw, 32a… Guide pin, 33…
Flat end set screw, 34 ... rear cylinder chamber, 35 ... gap, 36 ... gap, 37 ... front cylinder chamber, P1, P2 ... port, P21, P22 ... port, S ... section, θ ... lead angle, γ ... open angle , 101: movable type, 101a: core pin, 102: fixed type, 103: cavity,
104 ... gate, 105 ... hydraulic mechanism, 106 ... piston rod, 107
... Slope guide groove, 108 ... Sleeve, 109 ... Connecting rod, 10
9a: The other end of the connecting rod, 110: Connecting pin, α: Slope.

Claims (5)

[Claims] 1. A cylinder device having a basic structure of a single rod cylinder, comprising a head cover, at a cylinder chamber side facing an axis of a piston rod, which is longer than a stroke length of the piston rod and has an outer periphery. A guide rod formed with a male screw having a large lead angle is erected and fixed, while the piston rod comprises a main body and a guide plate abutted and fixed to the rear end face of the piston,
The main body portion has an inner diameter larger than a thread diameter of a male screw of the screw rod from the rear end face centering on the axis of the rod, and a length obtained by subtracting a thickness of the guide plate from a length of the screw rod. A deep axial hole is formed, and a female screw hole is formed in the guide plate at a position concentric with the axial hole and screwed into the screw rod with a gap serving as a fluid flow path interposed therebetween. A cylinder device. 2. The lead angle of a screw formed on a screw rod is 4
The cylinder device according to claim 1, wherein the angle is not less than 5 ° and less than 87 °. 3. A cylinder device having a basic structure of a single rod cylinder, wherein a rod cover has a female screw hole having a large lead angle centered on the axis of a rod through hole in a certain section on the cylinder chamber side. On the other hand, the piston rod has a male screw portion that is screwed into the front end face of the piston with a gap serving as a fluid flow path interposed between the female screw hole of the rod cover and the female screw hole, An axial hole deeper than the stroke length of the piston rod is formed from the rear end face centering on the axis of the rod, and a small protrusion is projected on the inner peripheral surface of the axial hole. At a position corresponding to the axial center of the piston rod in the axial hole of the piston rod with a gap serving as a fluid flow path interposed therebetween. A guide rod having a guide groove formed therein to guide the shaft in the axial direction while fitting the small projection of the rod in the axial direction to establish a screwing relationship between the male screw portion of the piston rod and the female screw hole of the rod cover is erected and fixed. A cylinder device characterized by having 4. The guide groove of the guide rod is formed linearly along the axial direction up to a position immediately before the male screw portion of the piston rod and the female screw hole of the rod cover are screwed,
The cylinder according to claim 3, wherein the groove width is formed so as to gradually increase along a movement locus in the axial direction accompanying the rotation of the small projection after the establishment of the screwing relationship on the front side of the position. apparatus. 5. The lead angle of a screw in a female screw hole formed on the rod cover side is 45 ° or more and less than 87 °.
Or the cylinder device of claim 4.