CN108202098A - Interior high pressure sealing is cut somebody's hair - Google Patents

Abstract

The invention discloses a kind of interior high pressure sealings to cut somebody's hair, including：It cuts somebody's hair outside；Inside cut somebody's hair；Wherein, outer cut somebody's hair is equivalent to traditional sleeve type and cuts somebody's hair, it inside cuts somebody's hair and is equivalent to traditional taper and cuts somebody's hair, the two is integrated into a structure for being similar to hydraulic cylinder, the conical head that end has of inside cutting somebody's hair can form pipe nozzle reliable sealing, and avoid pipe nozzle bulging based on this constraint with outer inner wall cooperation of cutting somebody's hair.

Description

Internal high pressure sealing push head

technical field

The invention relates to an internal high-pressure push head, which is a push head used in internal high-pressure forming equipment.

Background technique

Internal high pressure forming, also called hydroforming or hydroforming, is a material forming process that uses liquid as a forming medium to achieve the purpose of forming hollow parts by controlling internal pressure and material flow.

Internal high pressure forming is mainly used for the forming of pipe fittings (round pipes, square pipes, special-shaped pipes, etc., pipe fittings are called tube blanks in the forming process). The corresponding internal high pressure forming equipment includes molds, pushing devices and hydraulic devices. Usually, molds Consists of an upper mold and a lower mold, which are joined at the parting surface to form a mold cavity. During processing, the tube blank is put into the cavity part of the lower mold, and then the upper mold is lowered to constrain the tube blank in the cavity. Then one push head located at both ends of the tube blank bears against the corresponding end of the tube blank to provide the axial force of the tube blank, and the axial force is used for feeding.

One or two of the push heads have a hydraulic input pipe, which is used to fill the tube blank with liquid for bulging the tube blank. In order to obtain the designed wall thickness, there will be the feeding mentioned in the previous paragraph. The liquid pressure required for internal high pressure forming is relatively high, which requires a relatively high sealing ability generated by the joint between the push head and the end of the tube blank.

It can be seen from this that the hydraulic force is enough to deform the tube blank, that is to say, it has a very high pressure. Therefore, the pusher is not only used to provide the tube blank with axial force and liquid with a certain pressure, but also to ensure that it is compatible with the tube blank. The sealing of the nozzle, the sealing level should be greater than or equal to the sealing level allowed by the liquid pressure. If the sealing level is not enough, it will cause the pressure loss of the forming medium, resulting in insufficient forming of the tube blank, wrinkles and other defects, or the quality of the finished product is unqualified.

Commonly used push heads can be found in the Chinese patent document CN104438540A. The so-called punch is the push head. The punch is provided with a liquid inlet device. Partially penetrate into the tube opening of the tube blank, and realize joint sealing based on pushing. The conical surface is a wedge-shaped structure, which can generate axial thrust and radial tension, resulting in bulging of the tube opening. When the expansion is too large, the tube opening will be stuck at the end of the mold cavity, making it difficult to further push. In addition, the out-of-tolerance bulging requires further trimming of the tube opening, which may increase the burden of processing.

In view of this, in some implementations, such as the Chinese patent document CN106734493A, it requires that the tube blanks are all located in the mold cavity, the two ends of the mold cavity are formed as guide holes, and part of the pusher is configured as a guide post guided in the guide hole, here There is no wedge-shaped structure in the structure, and no radial tension will be generated. However, the tube wall is usually thin, and when the end of the tube is subjected to a large force, it may cause wrinkling or even flanging of the tube. The processing in the follow-up process is more difficult.

In some implementations, the end of the push head adopts a sleeve structure, and the end of the tube blank can be inserted into the sleeve structure, which is easy to form a seal, but the bottom of the sleeve and the end of the tube blank are still in a plane joint, which cannot solve the problem of the tube blank. Problems with end molding defects.

Contents of the invention

In view of this, the object of the present invention is to provide an internal high-pressure sealing pusher capable of effectively avoiding wrinkling defects or bulging defects at the end of the tube blank during forming.

According to an embodiment of the present invention, an internal high-pressure sealing push head is provided, including:

The main body of the outer pusher is a sleeve with one end closed, the closed end of the sleeve is the end of the outer pusher seat, and a first flow channel for introducing liquid is opened at the closed end; the middle wall of the inner cavity of the sleeve is opened a groove having a given width in the axial direction of the casing;

The inner push head is located in the sleeve to form a plunger axially guided to the sleeve. The inner push head has a second flow channel and a third flow channel, wherein the second flow channel is from the first end of the inner push head It is connected to the first hole on the side of the inner push head, and the first end is at the same end as the closed end; the third flow channel is connected to the second hole on the side of the inner push head from the second end of the inner push head, and the second end has a cone Shaped head, and form a positioning gap between the tube blank nozzle and the casing wall; the first hole and the second hole are located on the same side of the inner push head;

Wherein, when the first end is at the closed end, at least the first hole is biased on the closed side of the casing of the groove. During the working stroke of the inner push head, the first hole and the second hole are gradually connected through the groove, and the inner push head is working At the end dead center of the stroke, the first hole and the second hole are both interposed in the groove in the axial direction of the casing.

For the above-mentioned internal high-pressure sealing push head, optionally, the conical head is configured as follows: a spigot platform is provided at the bottom of the conical head, and the ring surface provided by the spigot platform engages with the end surface of the tube blank.

Optionally, the included angle between the generatrix of the conical head and the axis is 5°-10°.

Optionally, the height of the conical head is 0.215-0.247 times the inner diameter of the tube blank.

Optionally, the casing is used for the introduction of the tube blank nozzle;

A sealing ring is provided on the pipe section where the sleeve pipe and the tube opening of the tube blank are matched.

Optionally, the inner push head is provided with a left sealing ring and a right sealing ring;

The first hole and the second hole are between the left sealing ring and the right sealing ring;

Within the working stroke of the inner push head, the groove is between the left sealing ring and the right sealing ring.

Optionally, both the left sealing ring and the right sealing ring are Y-shaped sealing rings.

Optionally, the seat end of the outer pushing head is configured as follows: a mounting handle is axially connected to the closed end of the outer pushing head.

Optionally, the first flow channel includes an axial portion, and the axial portion constitutes a central hole of the mounting handle;

The second flow channel also includes a radial portion connected to the axial portion, so that a liquid injection hole is formed on the side of the mounting handle.

Optionally, the groove is an annular groove whose axis is the sleeve axis.

According to the embodiment of the present invention, the provided internal high-pressure sealing push head has an outer push head and an inner push head, compared with the existing push head, it is equivalent to the difference between the existing casing type push head and the conical push head. Assembly, and the combination of the inner pusher and the outer pusher is not a simple combination. Specifically, the outer push head and the inner push head form a plunger cylinder as a whole, the inner push head constitutes a plunger, and the inner push head has a first flow channel and a second flow channel, and the two flow channels are not directly connected; The push head constitutes the cylinder body, and there is a groove in the cylinder body for the communication between the first flow channel and the second flow channel. The communication is completed when the inner push head reaches a given position. In other words, the inner push head needs to run a given position first. The distance between the first flow channel and the second flow channel can be completed. This given distance is used for the tube blank nozzle to be constrained by the inner wall of the outer pushing head in advance, and then the tube blank nozzle can be reliably pushed out based on the pushing of the conical head. The constraint is between the inner pusher and the outer pusher. Constrained by the inner pusher and outer pusher, the tube orifice of the tube will not bulge, and because of the comprehensive clamping based on the inner and outer pusher, the sealing surface formed is more complicated, and the sealing surface area is relatively large, which greatly improves the sealing effect. ability.

Description of drawings

Fig. 1 is a schematic diagram of the main sectional structure of an internal high pressure sealing push head in an embodiment of the present invention.

Fig. 2 is a schematic diagram of the state before liquid injection after the push head and the tube blank are initially joined in one embodiment.

Fig. 3 is a schematic diagram of the state after the push head is fully engaged with the tube blank in one embodiment.

FIG. 4 is an enlarged view of part A of FIG. 3 .

Fig. 5 is a schematic diagram of the structure of the extrapolating head.

In the figure: 1. Screw hole, 2. Mounting handle, 3. Injection hole, 4. First flow channel, 5. Pusher body, 6. Sealing ring, 7. Second flow channel, 8. Third flow channel , 9. Groove, 10. Inner push head main body, 11. Seal ring, 12. Seat platform, 13. Seal ring, 14. Cavity, 15. Tapered head, 16. Tube blank.

Detailed ways

Referring to accompanying drawing 5 of the specification, it is shown in the figure that a kind of pusher head structure is similar to the existing sleeve-type pusher head. Compared with the traditional sleeve-type pusher head, the length of the pusher head main body 5 is Longer to accommodate the inner pusher.

For the inner push head, refer to the inner push head main body 10 shown in FIG. 1 , which is generally similar to the traditional conical push head.

The outer push head and the inner push head are both bodies of revolution. Correspondingly, the inner surface of the outer push head is an inner cylindrical surface, while the main part of the inner push head is a cylindrical structure, and its head end is the conical head 15 shown in the figure. It is a circular frustum structure as a whole, and the end part is rounded.

It can be understood that, for pipes and shafts with a certain axis, they have ends based on the direction of the axis, the direction around the axis is usually called the circumferential direction, the direction of the axis is called the axial direction, and the direction perpendicular to the axis is called called radial.

Regarding the pusher head, refer to the accompanying drawings 1~3 and 5 of the specification. It can be seen that its main part, that is, the main body 5 of the pusher head shown in the figure, is a sleeve with one end closed. This structure is similar to the cylinder body of a hydraulic cylinder. , the open end of the hydraulic cylinder is used to introduce the piston rod, and the other end is the seat end of the cylinder block or the cylinder seat. Correspondingly, the closed end of the sleeve is the seat end of the pusher head.

Different from the hydraulic cylinder, the first flow channel 4 for introducing fluid is not opened on the cylinder liner, but opened on the seat end of the external thrust head. In order to avoid movement interference in this field, the liquid injection hole 3 is usually opened on the side of the push head, therefore, for the first flow channel 4, it includes two parts, namely the axial part and the radial part, wherein the axial part is a blind hole , has a given depth, and its depth is mainly considered so that there will be no interference in position and movement when piping the liquid injection hole 3 . The radial part connects the axial part to the side of the push head for piping through the injection hole 3 .

In Fig. 1, there is a groove 9 on the wall surface of the middle part of the inner cavity of the casing determined by the main body of the outer pusher head 5. The groove 9 in the figure is an annular groove, and the axis of the annular groove is collinear with the axis of the main body 5 of the outer pusher head. . For such grooves 9 , the main parameters are width and depth, where the depth is based on radial dimensions and the width is based on axial dimensions.

If the rotation of the inner push head in the casing is not considered, a part of the annular groove can be reserved, such as a 90-degree sector ring groove.

In addition, in some implementations, the groove 9 may have a certain helix angle, or other state of curved arrangement, and its width is determined by a pair of vertical lines connecting groove walls according to conventional methods.

The groove 9 serves as a communication groove to realize the communication between the second flow channel 7 and the third flow channel 8 in FIG. 1 under a given condition. The second flow channel 7 and the third flow channel 8 are formed on the inner push head.

Regarding the inner push head, as mentioned above, it constitutes a plunger axially guided to the aforementioned sleeve, and accordingly, a moving pair is formed between the inner push head and the sleeve.

As can be seen in Figure 1, the upper side of the inner push head is provided with two liquid holes side by side, and the inner push head has a second flow channel 7 and a third flow channel 8, wherein the second flow channel 7 starts from the left end of the inner push head The liquid hole on the left side connected to the upper side of the inner push head is marked as the first hole, and the other liquid hole is marked as the second hole. The hole-forming method is also to form a hole by, for example, drilling, correspondingly starting from the left end and the upper side of the inner thrust head to form a hole.

The third channel 8 communicates from the right end of the inner push head in FIG. 1 to the aforementioned second hole. Obviously, it can be seen from Fig. 2 that the second flow channel 7 and the third flow channel 8 cannot be directly communicated, and they need to be in a given position to achieve complete communication, which is similar to the valve core. That is, the opening and closing of the valve is realized by changing the position. Overall, the push head shown in Figure 1 uses the principle of a two-position two-way valve. And the corresponding two-position two-way valve is a hydraulically controlled two-position two-way valve, but the hydraulic control port does not need to be provided separately, but directly uses the first flow channel 4 or the pressure oil port.

Wherein, in the structures shown in Figures 1 and 4, it can be clearly seen that the second end of the inner push head has a conical head 15. On the whole, the inner push head is similar to the traditional conical push head. The wedge-shaped principle of the conical surface seals the nozzle of the tube blank 16 . The difference is that, in the embodiment of the present invention, there is also an external push head, which can prevent the nozzle part of the tube blank 16 from being expanded by the reaction of the external push head.

Correspondingly, as shown in Figure 4, it can be seen in the figure that the nozzle positioning gap of the tube blank is formed between the conical head 15 and the casing wall surface, and the nozzle of the tube blank 16 is finally clamped in the positioning gap of the tube blank nozzle, which can Forms a good seal.

In addition, the first hole and the second hole are located on the same side of the inner push head. In FIG. 1 , the first hole and the second hole are on the upper busbar side of the inner push head.

Regarding the position of the first hole and the second hole on the inner pusher head, based on the principle of two-position two-way, when it is in the initial position shown in Figure 2, the first hole and the second hole are cut-off (ideal state, And a small amount of leakage does not affect the work of the inner push head).

In Figure 2, the inner push head is at the left dead center position. At this time, the cut-off is realized by the joint between the inner push head and the inner wall of the casing. As mentioned above, this cut-off does not require a complete cut-off, and a small amount of Leakage does not affect the work of the push head.

In the state shown in Figure 2, the first hole and the second hole are located on the left side of the groove 9, based on the aforementioned principle, if the groove 9 is wide enough, the second hole can be in the state shown in Figure 2 in the groove 9. Considering the amount of processing, the amount of processing should be reduced as much as possible. Therefore, in a preferred embodiment, in the initial state shown in Figure 2, the first hole and the second hole are located in the groove shown in Figure 2 9 on the left.

In the initial state, if the first flow channel 4 is fed with hydraulic oil or other types of internal expansion fluid, the fluid fills the first flow channel and the second flow channel, and the effective liquid level on the left side of the inner push head depends on the first flow channel 4 aperture. Assuming that the cross-sectional area of the first flow channel 4 is 1 square centimeter, for internal high pressure molding, its fluid pressure is usually tens of MPa, so a force of several thousand Newtons can be formed on an area of 1 square centimeter, which can push the inner pusher move to the right.

Once the inner push head is disengaged from the contact with the left closed bottom of the outer push head, the hydraulic effective area rapidly increases to the area of the left end face of the inner push head, and the thrust further increases.

The inner push head continues to move to the right, and the conical head 15 of the inner push head penetrates into the nozzle of the tube blank 16, and starts to squeeze the inner wall of the tube nozzle 16. For the traditional tapered push head, the nozzle of the tube blank 16 will bulge. shape, but in the embodiment of the present invention, the bulging of the nozzle of the tube blank 16 is restrained due to the constraints of the inner wall surface of the outer push head. The inner push head continues to move to the right and is extruded into the nozzle of the tube blank 16. Since the bulging of the tube mouth of the tube blank 16 is suppressed, the taper of the conical head 15 can be relatively small, and can penetrate deeper into the tube blank 16, thereby greatly increasing the area of the sealing joint surface and improving the sealing level.

During the working process of the inner push head, taking the structure shown in Figure 2 as an example, the second hole first communicates with the groove 9, but the first hole is still covered by the inner wall of the casing, and there is still no way to form a gap between the first hole and the second hole. effective connectivity. With the further progress of the inner push head, the first hole gradually communicates with the groove 9, and the area of the connecting surface becomes larger and larger until it reaches the maximum, so that the first hole and the second hole are fully connected, and the fluid passes through the first flow channel 4 and the second hole. The second flow channel 7 and the third flow channel 8 flow into the inner cavity of the tube blank.

As the conical head 15 and the tube blank 16 further engage, the received reaction force becomes larger and larger until it is balanced with the hydraulic pressure so that the inner pusher stops moving, and the stop moving position is the right dead point.

Since the taper of the conical head 15 is small and the friction angle is greater than the pressure angle, self-locking can be formed, so that the first hole and the second hole are interposed in the groove 9 to realize stable communication.

It can be understood that when the fluid initially enters the inner cavity of the tube blank, the right end of the inner push head in Figure 2 will not be subjected to hydraulic pressure due to the lack of liquid in the cavity.

In the aforementioned structure, in order to ensure that the inner thrust head has a definite right dead center, in the structure shown in Fig. 4, the inner push head main body 10 is a cylinder, the conical head 15 is a circular frustum structure, and the diameter of the large bottom of the circular frustum is less than The diameter of the cylinder, when the large bottom of the conical head 15 is coplanar with a bottom surface of the cylinder, and coaxial, will form the lip platform 12 as shown in Figure 1, and determine the table surface of the lip platform 12 is a circular surface. The notch table 12 is used to receive the end surface of the tube blank 16, so that the left dead center can have a definite position.

The annulus defined by the spigot platform 12 has the same geometrical shape as the end face annulus of the tube blank 6 .

Compared with the traditional conical push head, in the embodiment of the present invention, the angle between the generatrix of the conical head 15 and the axis is 5°~10°, which is smaller than the taper of the traditional conical push head, and can obtain a larger sealing interface. As far as the sealing joint is concerned, a second level of sealing is formed at the lip land 12 . Furthermore, the inner wall surface of the pusher head and the outer contour of the pipe opening of the tube blank 16 form a third-stage seal, thereby forming a reliable seal.

For the round platform, its height refers to the distance between its two bottoms. The height of the conical head 15 is 0.215~0.247 times the inner diameter of the pipe blank 16. The factor considered is that its height is compatible with the working stroke of the inner pusher head. And under the condition of relatively small working stroke, adapting to the taper of the aforementioned conical head 15 requires the conical head 15 to have a given height to achieve reliable clamping of the tube blank 16 .

Further, in order to improve the sealing ability, in the structure shown in FIG. 4 , the sleeve is used to introduce the nozzle of the tube blank 16 , and a sealing ring 13 is provided on the pipe section where the sleeve and the tube blank 16 are matched.

As shown in Figures 1 to 3, the inner push head is provided with a left sealing ring and a right sealing ring. The left and right here are only used to distinguish the two technical features, and the subsequent content has a description of the definite structure.

In FIG. 1 , the first hole and the second hole are between the left sealing ring and the right sealing ring, such as the sealing ring 6 and the sealing ring 11 shown in FIG. 1 .

Within the working stroke of the inner push head, the groove 9 is between the left sealing ring and the right sealing ring.

Both the left sealing ring and the right sealing ring are Y-shaped sealing rings. In addition, regarding the sealing ring 13, a Y-shaped sealing ring is also used. The section of the Y-shaped sealing ring is Y-shaped, which is a typical lip-shaped sealing ring. Widely used in reciprocating dynamic sealing devices, its service life is longer than that of O-rings. The applicable working pressure of the Y-shaped sealing ring is not more than 40MPa, and the working temperature is -30～80℃.

In the structure shown in FIG. 1 , the seat end of the pusher head is configured as follows: a mounting handle 2 is axially connected to the closed end of the pusher head for installation of the pusher head on hydraulic equipment. Regarding this structure, the traditional assembly structure of the push head and the hydraulic equipment can be adopted, and will not be repeated here.

Claims (10)

1. a kind of interior high pressure sealing is cut somebody's hair, which is characterized in that including：

It cuts somebody's hair outside, which is the casing of one end closing, and the blind end of the casing is extrapolation headstock end, and closing End is provided with the first flow for importing liquid；Wall surface is provided with a groove in the middle part of cannula cavity, which has casing axial direction Given width；

It inside cuts somebody's hair, the axially guiding plunger in casing is formed in casing, which is provided with second flow channel and third stream Road, wherein, the first end that second flow channel is cut somebody's hair in is connected to the first hole of interior side of cutting somebody's hair, and the first end and blind end are same End；Third flow channel second end for cutting somebody's hair in is cut somebody's hair the second hole of side in being connected to, which has a conical head, and with set Pipe nozzle position gap is formed between tube wall face；First hole is located at interior homonymy of cutting somebody's hair with the second hole；

Wherein, when first end is in blind end, at least the first hole is biased in the sleeve closure side of groove, impulse stroke of inside cutting somebody's hair In, the first hole is gradually connected with the second hole by groove, is inside cut somebody's hair in the end stop of impulse stroke, the first hole and the second hole It is axial in groove in casing.

2. interior high pressure sealing according to claim 1 is cut somebody's hair, which is characterized in that conical head is configured to：Conical head bottom is set There is stopping table, the anchor ring which provides and pipe nozzle end joined.

3. interior high pressure sealing according to claim 2 is cut somebody's hair, which is characterized in that the angle of conical head busbar and axis is 5 ° ~10°。

4. the interior high pressure sealing according to Claims 2 or 3 is cut somebody's hair, which is characterized in that the height of conical head is pipe nozzle 0.215 ~ 0.247 times of internal diameter.

5. the interior high pressure sealing according to Claims 2 or 3 is cut somebody's hair, which is characterized in that casing imports for pipe nozzle；

Sealing ring is equipped in the pipeline section of casing and the cooperation of pipe nozzle.

6. cut somebody's hair according to any interior high pressure sealing of claim 1 ~ 3, which is characterized in that inside cut somebody's hair equipped with left sealing ring With right sealing ring；

First hole and the second hole are between left sealing ring and right sealing ring；

In the impulse stroke cut somebody's hair inside, groove is between left sealing ring and right sealing ring.

7. interior high pressure sealing according to claim 6 is cut somebody's hair, which is characterized in that left sealing ring and right sealing ring are Y types Sealing ring.

8. cut somebody's hair according to any interior high pressure sealing of claim 1 ~ 3, which is characterized in that the seat end cut somebody's hair outside is configured to： The blind end cut somebody's hair outside axially connects an installing handle.

9. interior high pressure sealing according to claim 8 is cut somebody's hair, which is characterized in that first flow includes axial component, and Axial component forms the central duct of installing handle；

Second flow channel further includes the radial component for being connected to axial component, so as to form liquid injection hole in the side of installing handle.

10. cut somebody's hair according to any interior high pressure sealing of claim 1 ~ 3, which is characterized in that the groove is with quill Line is the annular groove of axis.