TWI660130B - Damper with piston-cylinder collision avoidance mechanism - Google Patents

Abstract

The invention relates to a damper, which comprises a cylinder, a piston, a piston rod, a buffer sleeve and an elastic pushing mechanism. Wherein, the piston is arranged in the cylinder body and divides the inside of the cylinder body into two oil chambers. The piston rod and the piston are linked and combined, and the piston rod defines a chamber, which is in communication with one of the oil chambers of the cylinder. The buffer sleeve is movably disposed on the piston, an opening at one end of the buffer sleeve communicates with the cavity of the piston rod, and an opening at the other end of the buffer sleeve communicates with the other oil chamber of the cylinder body, and the A radial channel is defined at the other end. The elastic pushing mechanism is used to elastically push the buffer shaft sleeve in a protruding position, so that when the buffer shaft sleeve has not abutted against the inner wall of the other oil chamber of the cylinder body, the other end of the buffer shaft sleeve remains convexly extended at Outside the piston is located in another oil chamber of the cylinder.

Description

Damper with mechanism for preventing piston from hitting cylinder

The invention relates to a damper, in particular to a damper having a buffer stroke and capable of preventing a piston from hitting a cylinder block.

According to the conventional hydraulic damper, it has a piston assembly which can move back and forth between a stretched position and a retracted position relative to the cylinder. In order to prevent the piston assembly from violently hitting the cylinder head when it reaches the retracted position, it is known that the hydraulic damper can be provided with a buffer device that can gradually reduce the oil flow rate, thereby slowing down the speed of fall and reducing movement noise, such as the Taiwan patent M470901 damper.

The invention provides a damper with a new structure, which includes a cylinder, a piston, a piston rod, a buffer shaft sleeve and an elastic pushing mechanism. The piston is arranged in the cylinder body, and the inside of the cylinder body is divided into a first oil chamber and a second oil chamber. The piston rod and the piston are linked and combined, and the piston rod defines a cavity, which is in communication with the first oil chamber of the cylinder body. The buffer shaft sleeve is movably disposed on the piston. The buffer shaft sleeve has a first end and a second end opposite to each other. One of the first ends of the buffer shaft sleeve is axially communicated with the cavity of the piston rod. An axial opening of the second end of the buffer shaft sleeve is in communication with the second oil chamber of the cylinder block, and a second channel of the buffer shaft sleeve is further defined with a radial passage, which is smaller than the axial opening of the second end. The elastic pushing mechanism is used for elastically pushing against the buffer shaft sleeve in a convex position, so that the second end of the buffer shaft sleeve remains protruding outside the piston and is located in the second oil chamber of the cylinder body. Wherein, the buffer shaft sleeve can advance with the piston to an inner wall of the second oil chamber abutting the cylinder block, so that the axial opening of the second end of the buffer shaft sleeve is closed by the inner wall of the second oil chamber, and the buffer The radial passage at the second end of the sleeve remains open to the second oil chamber. In this way, the hydraulic fluid can only enter the buffer oil jacket 4 from the radial channel 421, so its flow rate will start to slow down, thereby avoiding the piston from directly and violently hitting the cylinder head of the cylinder subsequently.

Preferably, the radial channel at the second end of the buffer sleeve is a hole, and the hole is defined in the pipe wall of the second end of the buffer sleeve; or, the radial channel at the second end of the buffer sleeve is a notch, notch An end surface defined on the second end of the buffer sleeve.

Preferably, the elastic pushing mechanism includes a restricting member, an elastic member and a buckle. The restricting member is provided on the piston rod. The elastic member is disposed between the restricting member and the buffer shaft sleeve to push the buffer shaft sleeve to the protruding position. The buckle sleeve is set on the outer peripheral wall of the first end of the buffer shaft sleeve. When the buffer shaft sleeve has not abutted against the inner wall of the second oil chamber of the cylinder block, the buckle ring is caught on the restricting member, so that the buffer shaft sleeve is on the elastic member The push is maintained in the protruding position.

Preferably, the restricting member includes an annular end cover and a bearing, the annular end cover is provided in an opening of the cavity of the piston rod, and the bearing is provided in the annular end cover to support the buffer shaft sleeve, and when the buffer shaft sleeve has not reached When leaning against the inner wall of the second oil chamber of the cylinder block, the retaining ring is caught on the bearing of the restricting member.

Preferably, when the buffer bushing abuts against the inner wall of the second oil chamber of the cylinder, the piston may continue to move relative to the buffer bushing to the inner wall of the second oil chamber of the cylinder, so that the The second end is retracted into the piston.

Preferably, the piston rod is provided with a first side hole and a second side hole at intervals along its length direction. Both the first side hole and the second side hole communicate with the chamber and the first oil chamber of the cylinder body. The cylinder is stretched to a buffering position, so that the first side hole of the piston rod is closed by an inner wall of the cylinder body, and the second side hole of the piston rod remains in communication with the first oil chamber of the cylinder body.

Preferably, the piston rod system penetrates the piston at least partially, and the piston has an end surface facing the first oil chamber of the cylinder block. The piston defines a groove on the end surface, and the groove communicates with the first oil chamber of the cylinder block and the piston rod. Second side hole.

1 to 9 show a preferred embodiment of the damper 100 of the present invention. As shown in FIG. 1, the damper 100 includes a cylinder block 1, a piston 2, a piston rod 3, a buffer sleeve 4, and an elastic pushing mechanism 5. The cylinder block 1 has a cylinder head 10 and 13 at each end. One of the cylinder heads 10 of the cylinder block 1 is fixed to the cylinder body by screwing, and the other cylinder head 13 of the cylinder block 1 is fixed to the cylinder body by welding. The piston 2 is disposed in the cylinder block 1 and partitions the interior of the cylinder block 1 into a first oil chamber 11 and a second oil chamber 12. The piston rod 3 is linked and combined with the piston 2. The buffer sleeve 4 is movably disposed on the piston 2. The elastic pushing mechanism 5 is used to elastically push the buffer shaft sleeve 4 in a protruding position (preferably as shown in FIG. 2 or FIG. 3), so that one end of the buffer shaft sleeve 4 remains protruding outside the piston 2 and is located The second oil chamber 12 of the cylinder block 1.

Please refer to the enlarged view of FIG. 2 and cooperate with FIG. 1. The piston rod 3 defines a cavity 30, and the cavity 30 communicates with the first oil chamber 11 of the cylinder 1. The buffer shaft sleeve 4 is movably disposed on the piston 2, and the buffer shaft sleeve 4 has a first end 41 and a second end 42 opposite to each other. Among them, one axial opening 410 of the first end 41 of the buffer sleeve 4 is in communication with the cavity 30 of the piston rod 3, and one axial opening 420 of the second end 42 of the buffer sleeve 4 is in communication with the second end of the cylinder 1. The oil chamber 12 communicates. In addition, the second end 42 of the buffer sleeve 4 further defines a radial channel 421, as shown in FIG. 5. The radial passage 421 of the second end 42 of the buffer sleeve 4 is far smaller than its axial opening 420.

FIG. 6 is a partial enlarged view of FIG. 2, which shows the hydraulic fluid when the buffer sleeve 4 is retracted with the piston 2 but has not abutted against an inner wall 121 of the second oil chamber 12 of the cylinder block 1. For example: silicone oil or mineral oil) can enter the buffer oil sleeve 4 through the axial opening 420 and the radial channel 421 of the second end 42 of the buffer shaft sleeve 4, and then enter the cavity 30 of the piston rod 3, and then into the cylinder body 1.之 第一 油 室 11。 11 first oil chamber. However, referring to FIG. 7 and cooperating with FIG. 3, when the buffer sleeve 4 continues to advance with the piston 2 to abut against the inner wall 121 of the second oil chamber 12 of the cylinder block 1, the second end of the buffer sleeve 4 The axial opening 420 of 42 is closed by the inner wall 121 of the second oil chamber 12, and the radial passage 421 of the second end 42 of the buffer shaft sleeve 4 remains open to the second oil chamber 12. At this time, the hydraulic fluid can only enter the buffer oil jacket 4 from the radial channel 421, so its flow rate will begin to slow down. As shown in FIG. 4 again, the piston 2 can continue to slowly move relative to the buffer sleeve 4 to the inner wall 121 of the second oil chamber 12 against the cylinder block 1 until the second end 42 of the buffer sleeve 4 will be fully retracted. In the piston 2, this can prevent the piston 2 from directly and violently hitting the cylinder head 13 of the cylinder block 1.

Referring back to FIG. 6, the elastic pushing mechanism 5 includes a restricting member 51, an elastic member 52 and a buckle 53. The limiting member 51 includes an annular end cover 511 and a bearing 512. The annular end cover 511 is embedded in an opening 301 of the cavity 30 of the piston rod 3. The bearing 512 is provided in the annular end cover 511 for supporting the buffer shaft sleeve 4. An elastic member 52 (for example, a compression spring) is provided between the bearing 512 of the restricting member 51 and an outer flange (not shown in the figure) of the second end 42 of the buffer shaft sleeve 4 to push the buffer shaft sleeve 4 to a convex position. Extending position. The retaining ring 53 is sleeved on the outer peripheral wall of the first end 41 of the buffer sleeve 4. When the buffer sleeve 4 has not abutted against the inner wall 121 of the second oil chamber 12 of the cylinder block 1, the retaining ring 53 is caught on the restricting member. The bearing 512 of 51 enables the buffer sleeve 4 to be maintained in a protruding position under the pushing of the elastic member 52, without rushing out of the piston 2 and detaching from the piston 2.

Referring to FIG. 1 and matching with FIG. 2, the piston rod 3 is provided with a first side hole 31 and a second side hole 32 at intervals along the length direction. Both the first side hole 31 and the second side hole 32 communicate with the chamber 30 and the first oil chamber 11 of the cylinder block 1, so that the hydraulic fluid that enters the chamber 30 of the piston rod 3 from the buffer sleeve 4 can pass through the piston rod 3 The first side hole 31 and a second side hole 32 enter the first oil chamber 11 of the cylinder block 1. In addition, the piston rod 3 is partially penetrated into the piston 2. The piston 2 has an end surface 21 facing the first oil chamber 11 of the cylinder block 1. The piston 2 defines a groove 22 on the end surface 21. The groove 22 communicates with the first oil chamber 11 of the cylinder block 1 and the second side hole 32 of the piston rod 3.

Referring to FIG. 8, the piston rod 3 can be stretched to a buffer position relative to the cylinder block 1, so that the first side hole 31 of the piston rod 3 is closed by an inner wall 101 of the cylinder head 10 of the cylinder block 1, and the piston rod 3 The two side holes 32 remain in communication with the first oil chamber 11 of the cylinder block 1. At this time, the hydraulic fluid in the chamber 30 of the piston rod 3 can only enter the first oil chamber 11 of the cylinder block 1 through the second side hole 32 of the piston rod 3, so the flow rate starts to slow down, and the piston rod 3 can be continuously slowed. It is stretched until the end surface 21 of the piston 2 abuts against the cylinder head 10 of the cylinder block 1, as shown in FIG. 9, so as to avoid the piston 2 from violently hitting the cylinder head 10 directly.

10 to 12 show another preferred embodiment of the present invention. The structure and operating mechanism in this embodiment are substantially the same as those in the previous embodiment. The only difference is the buffer sleeve 4 in the first preferred embodiment. The radial channel 421 of the second end 42 is a hole, which is defined in the tube wall of the second end 42 of the buffer sleeve 4, as shown in FIG. 5; however, in the second preferred embodiment, the The radial passage 421a of the second end 42 of the buffer sleeve 4a of the damper of the invention is a notch, which is defined on the end surface of the second end 42 of the buffer sleeve 4a.

As shown in FIG. 11, when the buffer sleeve 4 a is retracted along with the piston 2 but has not yet abutted against an inner wall 121 of the second oil chamber 12 of the cylinder block 1, the hydraulic fluid may be removed from the second portion of the buffer sleeve 4 a. The axial opening 420 and the radial passage 421 a of the end 42 enter the buffer oil jacket 4 a, continue to enter the cavity 30 of the piston rod 3, and then enter the first oil chamber 11 of the cylinder block 1. As shown in FIG. 12, when the buffer shaft sleeve 4 a continues to advance with the piston 2 to abut against the inner wall 121 of the second oil chamber 12 of the cylinder block 1, the axial end of the second end 42 of the buffer shaft sleeve 4 a opens. 420 is closed by the inner wall 121 of the second oil chamber 12, and the radial passage 421 a of the second end 42 of the buffer sleeve 4 a remains open to the second oil chamber 12. At this time, the hydraulic fluid can only enter the buffer oil jacket 4a from the radial channel 421a, so its flow rate will begin to slow down. Compared with the buffer oil jacket 4 used in the first preferred embodiment, the radial passage 421a of the buffer oil jacket 4a in the second preferred embodiment can be kept open at any time, and will not be covered by oil during use. Risk of clogging with impurities or foreign bodies.

With the above-mentioned setting, the damper of the present invention, through the use of its buffer shaft sleeve, enables the piston and piston rod of the damper to be buffered in the process of retracting or stretching, so as not to hit the cylinder head, so it can reduce Noise and delay life.

100‧‧‧ Damper

101‧‧‧inner wall

1‧‧‧cylinder block

10, 13‧‧‧ cylinder head

11‧‧‧The first oil room

12‧‧‧Second Oil Room

121‧‧‧ inner wall

2‧‧‧ Pistons

21‧‧‧face

22‧‧‧Ditch

3‧‧‧Piston rod

30‧‧‧ chamber

301‧‧‧ opening

31‧‧‧First side hole

32‧‧‧Second side hole

4, 4a‧‧‧ buffer shaft sleeve

41‧‧‧ the first end

410‧‧‧Axial opening

42‧‧‧ the second end

420‧‧‧ axial opening

421, 421a‧‧‧ radial channel

5‧‧‧ Flexible Arrival Agency

51‧‧‧Restrictions

511‧‧‧Ring end cap

512‧‧‧bearing

52‧‧‧Elastic piece

53‧‧‧ buckle

FIG. 1 is a schematic sectional structural view of a preferred embodiment of the damper of the present invention. FIG. 2 is a partially enlarged schematic diagram of the damper of FIG. 1. FIG. FIG. 3 is a schematic diagram of a retracting action of the damper of FIG. 2. FIG. 4 is a schematic diagram of another retracting action of the damper of FIG. 2. FIG. 5 is a perspective view of a buffer shaft sleeve of the damper of FIG. 1. FIG. FIG. 6 is a partially enlarged schematic diagram of the damper of FIG. 2. FIG. 7 is a partially enlarged schematic diagram of the damper of FIG. 3. FIG. 8 is a schematic drawing of a stretching action of the damper of FIG. 1. FIG. 9 is another schematic drawing of the stretching action of the damper of FIG. 1. FIG. FIG. 10 is a perspective view of a three-dimensional structure of a buffer sleeve according to another preferred embodiment of the damper of the present invention. FIG. 11 is similar to FIG. 6, and is a partially enlarged schematic diagram of the damper of FIG. 10. FIG. 12 is similar to FIG. 7, and is a partially enlarged schematic diagram of the damper of FIG. 10.

Claims (7)

A damper includes: a cylinder body; a piston disposed in the cylinder body, and partitioning the interior of the cylinder body into a first oil chamber and a second oil chamber; a piston rod, which is linked and combined with the piston, The piston rod defines a cavity, which is in communication with the first oil chamber of the cylinder body; an annular end cap is provided in an opening of the cavity of the piston rod and is adjacent to the piston; a buffer shaft A sleeve is movably disposed between the annular end cover and the piston. The buffer shaft sleeve has a first end and a second end opposite to each other. An axial opening of one of the first ends of the buffer shaft sleeve is connected to the axial end of the buffer shaft sleeve. The cavity of the piston rod communicates, and an axial opening at the second end of the buffer sleeve is in communication with the second oil chamber of the cylinder block, and the second end of the buffer sleeve further defines a radial passage; and an elasticity; A piece is provided between the annular end cover and the buffer shaft sleeve for elastically pushing the buffer shaft sleeve in a convex position, so that the second end of the buffer shaft sleeve remains protruding outside the piston and is located at The second oil chamber of the cylinder body; a buckle ring is sleeved on the outer peripheral wall of the first end of the buffer shaft sleeve to avoid the slow The shaft sleeve is detached from the annular end cover; wherein the buffer shaft sleeve can advance with the piston to an inner wall of the second oil chamber that abuts against the cylinder block, so that the second end of the buffer shaft sleeve is axially opened. It is closed by the inner wall of the second oil chamber, and the radial passage at the second end of the buffer shaft sleeve remains open to the second oil chamber. The damper according to item 1 of the scope of the patent application, wherein the radial channel at the second end of the buffer sleeve is a hole, and the hole penetrates a pipe wall provided at the second end of the buffer sleeve. The damper according to item 1 of the scope of the patent application, wherein the radial channel at the second end of the buffer sleeve is a notch, and the notch is defined at an end surface of the second end of the buffer sleeve. The damper according to item 1 of the patent application scope, wherein the annular end cover has a bearing inside, and the buffer sleeve passes through the bearing. The damper according to item 4 of the scope of patent application, wherein the second end of the buffer sleeve has an outer flange, the elastic element is sleeved on the buffer sleeve, and two ends of the elastic element are respectively abutted against the buffer sleeve. The outer flange of the buffer sleeve and the bearing. The damper according to item 1 of the scope of patent application, wherein the piston rod is provided with a first side hole and a second side hole at intervals along its length direction, and the first side hole and the second side hole communicate with the cavity. And the first oil chamber of the cylinder, the piston rod can be stretched to a buffer position relative to the cylinder, so that the first side hole of the piston rod is closed by an inner wall of the cylinder, and the first The two side holes remain in communication with the first oil chamber of the cylinder block. The damper according to item 1 of the scope of patent application, wherein the piston rod system at least partially penetrates the piston, the piston has an end surface facing the first oil chamber of the cylinder body, and the piston defines a recess on the end surface. A groove, which communicates with the first oil chamber of the cylinder block and the second side hole of the piston rod.