JP4996912B2 - Attenuator structure - Google Patents

Description

  The present invention relates to a damping part structure, and more particularly to an improvement of a damping part structure suitable for implementation in a piston part in a cylinder body in a hydraulic shock absorber.

  There have been various proposals for a damping part structure suitable for realizing a piston part in a cylinder body in a hydraulic shock absorber. Basically, there is a port as a flow path opened in a piston body as a valve seat member. It is supposed that it has an annular leaf valve that closes its downstream end so as to be openable and closable by an outer peripheral side bending portion.

  And in said damping | damping part structure, the annular leaf valve has obstruct | occluded the port when the outer peripheral side bending part is pressed on the piston body by the urging | biasing force from the coil spring arrange | positioned on the back side. However, when there is a hydraulic action through the port that overcomes the urging force of the coil spring, the outer side bending portion is bent to appear between the piston body and this gap is made to act as hydraulic oil. Passes through and generates a predetermined damping force.

  On the other hand, for example, as disclosed in Patent Document 1, in an attenuation part structure embodied in a recent piston part, the annular leaf valve is annular while the outer diameter is smaller than the outer diameter of the annular leaf valve. It is assumed that a valve restraining member, which has a greater bending rigidity than the leaf valve, is adjacent to the back surface, and that the tip of the coil spring is in contact with the back surface of the valve restraining member.

Therefore, in the damping part structure disclosed in Patent Document 1, when the piston speed in the cylinder body is in the very low speed region, the outer side bending part of the annular leaf valve is bent, so that a small gap appears. When the piston speed increases to the middle and high speed range, the valve holding member overcomes the biasing force of the coil spring and moves backward, and therefore the outer peripheral side bending portion of the annular leaf valve is greatly bent. In other words, large gaps appear, and the hydraulic oil passes through each gap, thereby realizing a predetermined damping action.

  However, when the damping part structure disclosed in Patent Document 1 described above including the conventional damping part structure is embodied, if the work is extremely elaborate, the product cost of the hydraulic shock absorber as a product is likely to increase. As a result, there is a risk that the versatility of the hydraulic shock absorber cannot be expected.

  That is, first, in the damping part structure disclosed in Patent Document 1, a valve restraining member that does not bend at all is adjacent to the back surface of the annular leaf valve. This valve restraining member is a coil spring. As long as it is transmitted to the annular leaf valve, the end face at the tip of the coil spring, that is, a flat surface with a frayed finish, is provided on the back of the annular leaf valve as long as the previous structure of the damping part. It is the same as the end face made of

  Therefore, as will be described under this premise, when the end face of the coil spring that contacts the back surface of the flat surface of the annular leaf valve is considered, in many cases, the end surface of the coil spring that has been frayed and finished is The actual situation is that the back surface of the annular leaf valve is not evenly contacted over the entire circumference, but is contacted at two locations that are so-called diametrically strong and weak.

  For this reason, when observing when the outer peripheral side bending portion of the annular leaf valve receiving the urging force from the coil spring starts to bend due to the action of cracking pressure, the annular leaf valve has other than the above two locations. The outer peripheral side bending portion of the portion not receiving the urging force from the coil spring starts to bend.

  As a result, the operation state set in advance in the annular leaf valve, that is, theoretically, the outer peripheral side bending portion of the annular leaf valve starts to bend uniformly over the entire circumference when cracking pressure is applied. Nevertheless, it cannot be said that the bending state according to this theory is not realized, and therefore it is not desired to generate the damping force as set.

  And in order to overcome this situation, the end face of the coil spring is scraped and finished so-called precisely, so that the end face of the coil spring is spread over the entire circumference on the back surface consisting of the flat surface of the annular leaf valve. It is desirable to ensure uniform contact, but this is not easy in practice, and if it is realized, the cost of parts in the coil spring is increased, and in the hydraulic shock absorber as a product. There is concern that the product cost will increase and its versatility cannot be expected.

  Thus, until now, when the outer peripheral side bent portion of the annular leaf valve starts to bend due to the action of cracking pressure, a phenomenon has occurred that the outer peripheral side bent portion of the annular leaf valve does not bend uniformly over the entire circumference. However, this phenomenon is an instantaneous phenomenon, and thereafter, it can be considered that the outer peripheral side bending portion of the annular leaf valve bends uniformly over the entire periphery, and thus disclosed in the above-mentioned Patent Document 1. In the present situation, the hydraulic shock absorber that embodies the structure of the damping part can realize the generation state of the damping force as set.

  The present invention was devised in view of such a current situation, and the object of the present invention is to solve a point that has not been regarded as a problem so far and to realize a hydraulic shock absorber having a higher degree of perfection. It is possible to provide an attenuation part structure that can be optimized and expected to improve its versatility.

In order to achieve the above-mentioned object, one means of the present invention includes a piston rod inserted into a cylinder body through a piston body so as to be freely retractable, a piston nut screwed to a lower end of the piston rod, and the cylinder body. A rod-side chamber and a piston-side chamber partitioned by the piston body, an extension-side port that is opened in the piston body and connects the rod-side chamber and the piston-side chamber, and an annular leaf valve that closes the extension-side port so that it can be opened and closed And a valve restraining member that has a larger bending rigidity than the leaf valve and abuts against the back surface of the leaf valve, and a coil spring that biases the leaf valve in a direction to be seated on the piston side via the valve restraining member. The coil spring has the base end held by the piston nut and is scraped at the tip. In a damping part structure in a hydraulic shock absorber in which an end surface made of a flat surface is brought into contact with a back surface made of a flat surface of the valve holding member, the leaf valve is in a stationary state without receiving a hydraulic action from the rod side chamber Sometimes, the tip of the coil spring has a flat end face that has been frayed, and has a sharp edge at the converging part that is frayed and gradually decreases in thickness, and a fray that is adjacent to this sharp edge from the rear side. It is characterized in that a gap is formed by being separated from the unfinished main body.
Similarly, the other means includes a valve seat member that defines the upstream side and the downstream side, a flow path that is opened in the valve seat member to connect the upstream side and the downstream side, and a downstream side of the flow path A valve body that closes the end so that the valve can be opened and closed, and a coil spring that is disposed on the back side of the valve body and biases the valve body in a direction to seat the valve body on the valve seat member. In the damping part structure in which the end surface consisting of a flat surface that is scraped and finished at the tip while being supported by the supporting member is brought into contact with the back surface consisting of the flat surface of the valve body, the valve body is in contact with the tip end in the flow path. A flat surface that is composed of a poppet type valve element that closes the opening of the flow path so that it can be opened and closed, and that the coil element is not subjected to the hydraulic action from the upstream side and is stationary. Kara There is a gap between the sharp end of the converging part that is scraped off and gradually reduces the thickness, and the non-frayed main body part that is adjacent to the sharp tip from the back side at the tip having an end face. It is characterized by having.

According to the invention of the claims, the scene in which the end face comprising a flat surface which is finished leveling of the coil spring is in contact with the back surface consisting of a flat surface of the valve body, or valve body made of a poppet-type valve body made of leaf valve The tip of the coil spring has an end face that has been frayed, and has a sharp end at the converging part that has been frayed and gradually thins the wall, and the main part that has not been frayed close to this point from the rear side. because are spaced has a gap between the, the situation where the biasing force of the coil spring is transmitted in a number becomes three places or more sites than two positions with respect to the back of the valve body.

Therefore, each valve body is fixed to the piston body or the valve seat member in a state where it receives a substantially uniform biasing force in the circumferential direction from the coil spring. Therefore, the valve body is coil spring by the action of the cracking pressure. When retreating against the urging force, the retreat is uniformly performed over the entire circumference, and the generation state of the damping force as set can be realized.

  As a result, according to the present invention, the end face at the tip of the coil spring is subjected to a conventional scraping finish, so that it is not necessary to precisely scrape and finish, so that the cost of parts in the coil spring can be increased without increasing the cost. It becomes possible not to unnecessarily increase the product cost of the hydraulic shock absorber.

  In addition to the conventional coil springs, the tip of the coil spring has a sharpened end face, and the sharpened end of the converging part that has been scraped to gradually reduce the wall thickness and the sharpened tip. In the present invention, it is said that the coil spring has the above-mentioned gap, whereas it is considered that the main body part that has not been frayed into contact with each other is brought into contact with each other and no gap appears between them. Since it is indispensable, there is no need for labor to manufacture the coil spring as a part, and the cost of the part in the coil spring can be reduced.

  Hereinafter, the present invention will be described based on the illustrated embodiment. As shown in FIG. 1, the structure of the damping portion according to the present invention is embodied in a piston portion of a hydraulic shock absorber as an embodiment thereof. It is going to be.

  That is, in the hydraulic shock absorber, even if the hydraulic shock absorber is formed as a single cylinder type or a double cylinder type, the cylinder body 1 has a lower end which is the lower end side in the figure of the piston rod 2 which is a rod body. It is said that the side is inserted so that it can appear and disappear.

  The lower end fitting portion 2a of the piston rod 2 positioned in the cylinder body 1 holds a piston portion slidably accommodated in the cylinder body 1, and at this time, the piston portion The piston body 3 that is a valve seat member that forms a cylinder body 1 defines a rod-side chamber R1 that is upstream and a piston-side chamber R2 that is downstream.

  In addition, the piston body 3 is formed by opening the expansion side port 3a that is a flow path that allows the rod side chamber R1 to communicate with the piston side oil R2, and the downstream side that is the lower end in the drawing of the expansion side port 3a. The side end is closed so as to be openable and closable by an annular leaf valve 4 which is a valve body which is an extension side damping valve.

  At this time, the annular leaf valve 4 is seated on the piston body 3 by the urging force of the coil spring 5 disposed on the back side of the annular leaf valve 4, and closes the above-mentioned extension side port 3a. It is said.

  The coil spring 5 is assumed to be carried by a lower end flange 6a of a piston nut 6 screwed into a lower end fitting portion 2a of the piston rod 2 as shown in the drawing. The piston nut 6 is configured such that the inner peripheral side fixing portion 4a of the annular leaf valve 4 is sandwiched between the piston nut 6 and the inner peripheral side boss portion 3b of the piston body 3 at the upper end thereof.

  Incidentally, the arrangement state of the annular leaf valve 4 to the piston body 3 is considered. From the point of view of the present invention, the annular leaf valve 4 penetrates the shaft core portion of the piston body 3 and the coil spring 5 The piston rod 6 carrying the base end may be provided in a floating structure that is movably interposed on the outer periphery of the lower end fitting portion 2a of the piston rod 2 on which the piston nut 6 is screwed.

  Further, in the illustrated embodiment, the piston body 3 includes a pressure side port 3c that is a flow path that allows the piston side chamber R2 to communicate with the rod side chamber R1, and an upper end of the pressure side port 3c in the drawing. The downstream end is closed with an annular leaf valve 7 serving as an extension check valve so as to be opened and closed.

  At this time, the annular leaf valve 7 is energized from the back side by the non-return spring 7a and is seated on the piston body 3. However, the flow of the hydraulic oil from the rod side chamber R1 to the extension side port 3a is prevented. An opening 7b is provided so as not to exist.

  Therefore, in the piston portion formed as described above, when the piston body 3 that is the valve seat member moves upward in the cylinder body 1, the hydraulic oil in the rod side chamber R1 that is the upstream side is moved to the piston body 3. The bent portion of the annular leaf valve 4 as a valve element that flows into the opening side port 3a of the opening and closes the downstream end of the extension side port 3a so as to be openable and closable is resisted against the biasing force of the coil spring 5. Thus, a gap appears between the piston body 3 and the hydraulic oil flows out into the piston side chamber R2 on the downstream side through this gap, and a predetermined extension side damping force is generated. It will be.

  Incidentally, as will be described later, in the illustrated embodiment, the annular leaf valve 4 has a valve restraining member 8 adjacent to the back surface, and the outer peripheral side bending portion is coiled when the piston speed is in the very low speed region. The spring 5 is bent without being bent to generate an extension side damping force in a very low speed region.

  Contrary to the above, at the time of pressure side operation in which the piston body 3 descends in the cylinder body 1, the hydraulic oil in the piston side chamber R2 flows into the pressure side port 3c of the piston body 3 and the downstream side of the pressure side port 3c. The annular leaf valve 7 serving as a check valve that closes the end in an openable / closable manner is bent to cause a gap between the piston body 3 and the hydraulic oil flows into the rod side chamber R1 through this gap.

  Incidentally, although the compression side damping force during the compression side operation is not illustrated, for example, when the base valve portion is disposed at the bottom end portion of the cylinder body 1, in many cases, It would be generated with a pressure side damping valve disposed.

  By the way, in the above-described piston portion, the coil spring 5 urges the annular leaf valve 4 from the back side. However, in the illustrated embodiment, a valve holding member 8 is provided on the back surface of the annular leaf valve 4. Therefore, the tip that is the upper end of the coil spring 5 in the drawing is basically in a state of biasing the annular leaf valve 4 through the valve restraining member 8. .

  Incidentally, the valve restraining member 8 is formed so as not to be easily bent with a material having a bending rigidity larger than that of the annular leaf valve 4, and in the illustrated embodiment, the outer diameter is the outer diameter of the annular leaf valve 4. It is supposed to be adjacent to the back surface of the annular leaf valve 4 while being smaller.

  The outer diameter of the valve restraining member 8 may be substantially the same as the outer diameter of the annular leaf valve 4. In this case, the outer diameter of the annular leaf valve 4 is smaller than that in the above case. Thus, the outer peripheral side bent portion in the annular leaf valve 4 is further suppressed, and therefore, the outer peripheral side bent portion in the annular leaf valve 4 will be difficult to be bent in a very low speed region.

  As described above, in the illustrated embodiment, the coil spring 5 basically urges the annular leaf valve 4 from the rear side via the valve restraining member 8, but has the valve restraining member 8. Regardless of whether or not, in order to embody the present invention, it is configured as follows.

  That is, when the annular leaf valve 4 is in a stationary state without receiving cracking pressure as a hydraulic action from the upstream side, as shown in (1) of the row (B) in FIG. In the tip 5a having an end surface made of a flat surface, the tip 5c of the converging part 5b that is scraped off and gradually decreases in thickness, and the tip 5c is not scraped off from the back side. It is assumed that a gap S is formed between the main body 5d and the main body 5d.

  Therefore, in the present invention, in the present invention, the pointed portion 5c of the converging portion 5b in which the coil spring 5 is scraped and gradually becomes thinner, and the body portion that is not scraped and is adjacent to the pointed portion 5c from the rear side. It will be briefly described that the gap 5d is separated from the gap 5d.

  That is, row (A) in FIG. 2 shows the properties of the conventional coil spring 50, and row (B) in FIG. 2 shows the properties of the coil spring 5 in the present invention. In addition, in the conventional coil spring 50 shown in the row (A) in FIG. 2, the tip end portion 51 of the converging portion 52, which has an end face that has been frayed and has been frayed and gradually becomes thinner. 53 and the pointed portion 53 come into contact with the main body portion 54 that has not been scraped from the back side, and consideration is given to prevent a gap from appearing between them.

  From this fact, when the situation where the end face made of the flat surface of the conventional coil spring 50 is in contact with the back face made of the flat surface of the annular leaf valve is monitored, (2) in the row (A) in FIG. As shown in Fig. 4, the situation of contact at two locations in the circumferential direction indicated by reference symbols a and b could be measured.

  When cracking pressure is applied to the annular leaf valve, the urging force from the coil spring becomes two arc-shaped distribution states as shown in (3) of the row (A) in FIG. It could be measured to appear.

  On the other hand, when the situation in which the end face made of the flat surface subjected to scraping in the coil spring 5 of the present invention contacts the back surface made of the flat face of the annular leaf valve is monitored, (2) in the row (B) in FIG. As shown in Fig. 5, the situation of contact at three places indicated by symbols a, b, and c more than two places in the circumferential direction could be measured.

  When the cracking pressure is applied to the annular leaf valve 4, the urging force from the coil spring 5 becomes a substantially circular distribution state as shown in (3) of the row (B) in FIG. It could be measured to appear.

  Incidentally, for example, when it is assumed that the gap S is made of a flexible member that fills the fluid, when the flexible member is crushed, the urging force of the coil spring 5 is circumferentially applied at the distal end portion 5a. It can also be said that it is made uniform and acts on the annular leaf valve 4.

  Therefore, from this, in the situation where the annular leaf valve is urged by the conventional coil spring 50, the outer peripheral side bending portion of the annular leaf valve receiving the urging force from the coil spring 50 on the back surface is the cracking pressure. When it starts to bend due to the action, in the annular leaf valve, the outer peripheral side bending portion of the portion not receiving the urging force from the coil spring 50 other than the above two locations starts to bend.

  Therefore, the operation state set in advance in the annular leaf valve is set, that is, in terms of setting, the outer peripheral side bending portion of the annular leaf valve starts to bend uniformly over the entire circumference when cracking pressure is applied. Nevertheless, it can be said that the bending state according to this setting has not been realized, and therefore the generation of the damping force according to the setting cannot be expected.

On the other hand, in the present invention, the urging force from the coil spring 5 acts at three or more locations that are greater than two locations in the circumferential direction on the back surface of the annular leaf valve 4. When the annular leaf valve 4 is retracted against the urging force of the coil spring 5 by the action of the cracking pressure, it is fixed to the entire circumference by the urging force acting substantially uniformly in the circumferential direction. Accordingly, it is possible to realize the state of generation of the damping force as set.

  From the above, it can be understood that the coil spring 5 according to the present invention is sufficient if the tip end portion 5a having the end face subjected to the fraying finish has the gap S, but the present invention is effectively embodied. For example, it can be said that the following conditions are satisfied.

That is, for example, when the coil spring 5 has a wire diameter of 3 mm and a winding diameter of 25 mm , it has been confirmed that the present invention can be most effectively embodied when the gap S is 0.2 mm .

  The gap S must be formed at the distal end portion 5a of the coil spring 5, and even if it is formed at the proximal end portion of the coil spring 5 carried by the piston nut 6, the present invention can be embodied. Don't be.

  However, as long as the gap S is formed at the distal end portion 5a of the coil spring 5, even if the gap S is formed together with the proximal end portion of the coil spring 5, it does not hinder the realization of the present invention.

  On the contrary, it can be said that it is preferable that the gap S is formed at both ends of the coil spring 5 from the viewpoint of avoiding so-called misassembly when assembling the damping portion structure.

In view of the above, the coil spring 5 can embody the intention of the present invention as long as the valve body is energized. For example, as shown in FIG. 3, the valve body is attached to the valve seat member. The poppet type valve element 9 closes the opening of the channel so that the opening of the channel can be opened and closed while the tip end is present in the opening channel, and the coil spring 5 is disposed on the back surface of the poppet type valve element 9 on the flat surface. An end surface made of a flat surface that has been scraped off may be brought into contact.

It is a fragmentary longitudinal cross-section which shows the piston part in the cylinder in the hydraulic shock absorber which actualized the damping | damping part structure by this invention. FIG. 2 is a principle diagram showing a state of transmission of urging force from a coil spring to a valve body, in which (A) row shows a case of a conventional coil spring, and (B) row is a case of a coil spring of the present invention. FIG. It is a fragmentary longitudinal cross-section which shows other embodiment which actualized the attenuation | damping part structure by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder body 2 Piston rod 2a Lower end fitting part 3 Piston body which is a valve seat member 3a Expansion side port 3b which is a flow path 4 Inner peripheral side boss part 4 Annular leaf valve which is a valve body 4a Inner peripheral side fixed part 5 Coil spring 5a Tip part 5b Converging part 5c Pointed part 5d Main body part 6 Piston nut as a supporting member 8 Valve restraining member 9 Poppet R1 Rod side chamber R2 upstream side Piston side chamber S downstream side S Gap

Claims (3)

A piston rod inserted into and retracted through the piston body through the piston body; a piston nut screwed to the lower end of the piston rod; a rod side chamber and a piston side chamber partitioned by the piston body in the cylinder body; and the piston An extension port that is opened in the body to allow the rod side chamber and the piston side chamber to communicate with each other, an annular leaf valve that closes the extension side port so as to be openable and closable, and has a larger bending rigidity than the leaf valve. A valve holding member that abuts, and a coil spring that urges the leaf valve in a direction to be seated on the piston side via the valve holding member, and the coil spring holds the base end on the piston nut. The end face consisting of a flat face that has been frayed at the tip is the flat face of the valve restraining member. In the damping part structure in the hydraulic shock absorber that is in contact with the back surface, when the leaf valve is in a stationary state without receiving the hydraulic action from the rod side chamber, the end surface formed of a flat surface that has been scraped off of the coil spring The tip of the converging part that is scraped off and gradually thins the wall is separated from the non-frayed body part adjacent to the tip from the rear side to form a gap. A damping part structure in a hydraulic shock absorber . The inner peripheral side fixed part of the annular leaf valve is sandwiched between the inner peripheral side boss part of the piston body and the upper end of the piston nut carrying the base end of the coil spring, or the annular leaf valve is fitted to the lower end of the piston rod. The damping part structure in the hydraulic shock absorber according to claim 1, wherein the damping part structure is movably provided on an outer periphery of the joint part . A valve seat member that defines the upstream side and the downstream side, a flow path that is opened in the valve seat member to connect the upstream side and the downstream side, and a downstream end of the flow path is closed so as to be openable and closable. A valve spring, and a coil spring that is disposed on the back side of the valve body and urges the valve body in a direction to seat the valve body on the valve seat member. In the damping part structure in which the end surface consisting of a flat surface that has been scraped is brought into contact with the back surface consisting of the flat surface of the valve body, the valve body can open and close the opening of the flow path while the pointed end is present in the flow path A tip portion having an end surface composed of a flat-finished surface of a coil spring when the valve body is in a stationary state without receiving a hydraulic action from the upstream side. There is a gap between the pointed end portion of the converged portion that is scraped off and gradually thins the wall and the body portion that is not scraped off and is adjacent to the pointed end portion from the back side. Attenuating part structure characterized by

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