A two-stage cylinder

Abstract

The present invention provides a two-stage cylinder, comprising a cylinder block, wherein a moving component accommodating cavity is arranged inside the cylinder block, and a first moving component and a second moving component are arranged inside the moving component accommodating cavity; the first moving component includes a piston rod and a piston for driving the piston rod to move axially along the cylinder block; the second moving component includes a movable rod, the piston rod is of a hollow structure, and the front end of the movable rod is movably arranged inside the piston rod; a locking device for locking the movable rod is arranged at the rear end of the cylinder block. When the movable rod is locked, the piston rod moves forward until the rear end of the piston rod moves forward to the front end of the movable rod, and the piston rod extends to the first stage of stroke. When the movable rod is unlocked, the piston rod drives the movable rod to move forward until the piston abuts against the front wall of the moving component accommodating cavity, and the piston rod extends to the second stage of stroke. The present invention realizes two-stage telescoping.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of pneumatic actuators, and more particularly to a two-stage cylinder. Background Art

[0002] Existing cylinders are generally of one-stage type, reaching the maximum stroke when extended and having only one stroke. Such cylinders cannot meet the requirements in special scenarios, such as in the fire-fighting doors and windows industry. Doors and windows not only have the function of transmitting light, but also play a role in ventilation and exchanging indoor and outdoor air. Especially in case of a fire, the doors and windows should be opened to the maximum to quickly exhaust the high-temperature and toxic gases indoors and relieve the indoor environment. Therefore, the requirements for the opening amplitude of doors and windows are different during daily ventilation and fire-fighting ventilation. Thus, there is an urgent need to develop a cylinder with two strokes. Summary of the Invention

[0003] The purpose of the present invention is to provide a two-stage cylinder, which realizes two-stage stroke control.

[0004] The two-stage cylinder provided by the present invention includes a cylinder body. A moving component accommodation cavity is arranged inside the cylinder body, and a first moving component and a second moving component are arranged inside the moving component accommodation cavity. The first moving component includes a piston rod and a piston for driving the piston rod to move axially along the cylinder body. The second moving component includes a movable rod. The piston rod is of a hollow structure, and the front end of the movable rod is movably arranged inside the piston rod. A locking device for locking the movable rod is arranged at the rear end of the cylinder body. When the movable rod is locked, the piston rod moves forward until the rear end of the piston rod moves forward to the front end of the movable rod, and the piston rod extends to the first stroke. When the movable rod is unlocked, the piston rod drives the movable rod to move forward until the piston abuts against the front wall of the moving component accommodation cavity, and the piston rod extends to the second stroke.

[0005] After the piston rod moves to the first stroke, due to the locking of the movable rod, the piston rod is blocked by the movable rod. In the specific scenario of applying the two-stage cylinder, it is not likely that the piston rod extends too long due to an accident. Only after the piston rod is unlocked can the piston rod extend to the second stroke.

[0006] Preferably, a second locking pin is arranged at the rear end of the movable rod, and a second locking groove is arranged on the outer wall at the rear end of the second locking pin. A second rear accommodation cavity is arranged at the rear end of the cylinder body, and the locking device is a second locking component, and the second locking component is arranged inside the second rear accommodation cavity.

[0007] The second locking assembly includes a second limiting steel ball, a second rear locking slider, a second rear locking slider return spring, a second steel ball support plug, and a second steel ball support plug return spring; the second rear locking slider is disposed in the second rear accommodation cavity so as to be movable back and forth, and the second rear locking slider return spring is used to urge the second rear locking slider to move forward and reset; a second steel ball support plug accommodation cavity is provided at the front end of the second rear locking slider, the second steel ball support plug is disposed in the second steel ball support plug accommodation cavity, and the second steel ball support plug return spring is used to urge the second steel ball support plug to move forward and reset; the second limiting steel ball is disposed close to the front wall of the second rear accommodation cavity.

[0008] When locking, the second locking pin presses the second steel ball support plug backward, and the second limiting steel ball is snapped into the second locking groove; when unlocking, the gas entering the second rear accommodation cavity pushes the second rear locking slider to move backward, the second limiting steel ball disengages from the second locking groove, the second steel ball support plug resets under the action of the second steel ball support plug return spring, and the second limiting steel ball is restricted within the space formed by the second steel ball support plug, the second rear locking slider, and the inner wall of the second rear accommodation cavity.

[0009] To prevent the second limiting steel ball from disengaging from the locking groove during locking, the gas pressure in the second rear accommodation cavity of the present invention is less than the acting force of the second rear locking slider return spring, and the second rear locking slider abuts against the front wall of the second rear accommodation cavity under the action of the second rear locking slider return spring, restricting the second limiting steel ball from disengaging from the second locking groove.

[0010] To prevent the piston rod from being pulled out to the first stroke due to an accidental event, the piston rod of the present invention is fixedly locked, a first locking pin is provided at the rear end of the piston rod, and a first locking groove is provided on the outer wall of the rear end of the first locking pin; a first rear accommodation cavity is further provided at the rear end of the cylinder block in front of the second rear accommodation cavity, and a first locking assembly is installed in the first rear accommodation cavity.

[0011] The first locking assembly includes a first limiting steel ball, a first rear locking slider, a first rear locking slider return spring, a first steel ball support plug, and a first steel ball support plug return spring; the first rear locking slider is disposed in the first rear accommodation cavity so as to be movable back and forth, and the first rear locking slider return spring is used to urge the first rear locking slider to move forward and reset; a first steel ball support plug accommodation cavity is provided at the front end of the first rear locking slider, the first steel ball support plug is disposed in the first steel ball support plug accommodation cavity, and the first steel ball support plug return spring is used to urge the first steel ball support plug to move forward and reset; the first limiting steel ball is disposed close to the front wall of the first rear accommodation cavity.

[0012] When locked, the first locking pin presses the first steel ball support plug backward, and the first limiting steel ball snaps into the first locking groove. When unlocking, the gas entering the first rear accommodation cavity pushes the first rear locking slider backward, the first limiting steel ball disengages from the first locking groove, and the first steel ball support plug resets under the action of the first steel ball support plug return spring. The first limiting steel ball is restricted in the space formed by the first steel ball support plug, the first rear locking slider, and the inner wall of the first rear accommodation cavity.

[0013] To prevent the first limiting steel ball from disengaging from the locking groove when locked, the gas pressure in the first rear accommodation cavity of the present invention is less than the acting force of the first rear locking slider return spring. The first rear locking slider abuts against the front wall of the first rear accommodation cavity under the action of the first rear locking slider return spring, restricting the first limiting steel ball from disengaging from the first locking groove.

[0014] Preferably, a high-pressure opening valve is installed on the housing of the second locking assembly. The high-pressure opening valve includes a valve body, a high-pressure valve piston, and a high-pressure valve return spring. A high-pressure valve piston accommodation cavity with a pressure relief hole is formed in the valve body. The high-pressure valve piston is arranged in the high-pressure valve piston accommodation cavity, dividing the high-pressure valve piston accommodation cavity into front and rear parts; the high-pressure valve piston accommodation cavity is respectively communicated with the first rear accommodation cavity and the second rear accommodation cavity through the second air passage and the third air passage, and the high-pressure valve piston accommodation cavity is also communicated with the second rear accommodation cavity through the fourth air passage;

[0015] When locked, the first rear accommodation cavity is depressurized, the high-pressure valve piston resets under the action of the high-pressure valve return spring, the high-pressure valve piston separates the second air passage and the third air passage, and the fourth air passage, the rear part of the high-pressure valve piston accommodation cavity, and the pressure relief hole are communicated. The second rear accommodation cavity is depressurized through the fourth air passage, the high-pressure valve piston accommodation cavity, and the pressure relief hole; when unlocking, the gas pressure entering the front part of the high-pressure valve piston accommodation cavity from the first rear accommodation cavity through the second air passage is greater than the acting force of the high-pressure valve return spring, so that the second air passage, the front part of the high-pressure valve piston accommodation cavity, and the third air passage are communicated, and the high-pressure valve piston blocks the fourth air passage.

[0016] After setting the high-pressure opening valve, the unlocking of the piston rod and the unlocking of the movable rod can be carried out simultaneously or separately. When the gas pressure introduced into the first rear accommodation cavity is greater than the acting force of the high-pressure valve return spring, the gas enters the high-pressure valve piston accommodation cavity through the second air passage, and then enters the second rear accommodation cavity through the third air passage. At this time, the piston rod and the movable rod are basically unlocked synchronously. At this time, the piston rod can be pushed out by the piston at one time, rather than having a two-stage stroke. It is also possible to first introduce gas with a slightly lower pressure, which is not enough to push the high-pressure valve piston, so as to unlock the piston rod first, and then introduce gas with a slightly higher pressure to push the high-pressure valve piston and unlock the movable rod. It should be noted that the "high pressure" in the high-pressure opening valve does not mean how large the pressure of the valve is and what range it meets, but is just a name. How much pressure of gas needs to be introduced to push the high-pressure valve piston mainly depends on the acting force of the high-pressure valve return spring. That is to say, after setting the high-pressure opening valve, the present invention can be used as a two-stage cylinder or as an ordinary one-stage cylinder, and can be applied to a variety of uses.

[0017] Preferably, the movement component accommodation cavity is divided into front and rear parts by the piston; the first rear accommodation cavity is communicated with the first air inlet through the first air passage and the rear part of the movement component accommodation cavity. Thus, when compressed gas is introduced into the cylinder, on the one hand, the first locking component and the second locking component are unlocked, so as to unlock the piston rod and the movable rod, and on the other hand, the piston rod and the movable rod are pushed forward, and only one air source is needed.

[0018] Preferably, when unlocking, the piston rod is unlocked before the movable rod, that is, the gas pressure introduced into the first air inlet is greater than the acting force of the first rear lock slider return spring, so as to unlock the piston rod, and then pressurize until the air pressure is greater than the acting force of the high-pressure valve return spring, so as to unlock the movable rod.

[0019] Preferably, a first steel ball accommodation groove for placing the first limit steel ball is provided at the front end of the first rear accommodation cavity, and an inclined surface for facilitating the first limit steel ball to enter and exit the first steel ball accommodation groove is provided at the front end of the first steel ball accommodation groove; and / or, a second steel ball accommodation groove for placing the second limit steel ball is provided at the front end of the second rear accommodation cavity, and an inclined surface for facilitating the second limit steel ball to enter and exit the second steel ball accommodation groove is provided at the front end of the second steel ball accommodation groove.

[0020] Preferably, the first rear accommodation cavity is provided on the rear end cover at the rear end of the cylinder block. The rear end of the first rear lock slider extends out of the rear end cover, and a second locking component housing is installed at the rear end of the first rear lock slider. The second rear accommodation cavity is provided at the rear end of the second locking component housing.

[0021] Preferably, a sealing ring is provided between the first rear lock slider and the second locking component housing.

[0022] Preferably, the inner diameter of the first locking pin is smaller than the inner diameter of the piston rod, so as to form a first limiting end face at the front end of the first locking pin, and a limiting protrusion cooperating with the first limiting end face is provided at the front end of the movable rod; the outer diameter of the second locking pin is larger than the outer diameter of the movable rod, so as to form a second limiting end face at the front end of the second locking pin, and the second limiting end face cooperates with the rear end face of the first locking pin.

[0023] Preferably, the outer diameter of the movable rod matches the inner diameter of the first locking pin. When the external force is less than the frictional force between the two, the two move together. When the external force is greater than the frictional force between the two, the two can move relative to each other.

[0024] Preferably, a front locking groove is provided on the piston rod; a front accommodating cavity is provided on the front end cover at the front end of the cylinder block, and a front locking assembly is installed in the front accommodating cavity; the front locking assembly includes a front locking slider, a front locking steel ball, and a front locking slider return spring;

[0025] The front locking slider is movably arranged in the front accommodating cavity, and the front locking slider return spring is used to urge the front locking slider to move backward and reset; the front locking steel ball is arranged close to the rear wall of the front accommodating cavity; when locking, the front locking steel ball is stuck into the front locking groove; when unlocking, the gas entering the front accommodating cavity pushes the front locking slider to move forward, and the front locking steel ball disengages from the front locking groove.

[0026] Preferably, the front accommodating cavity is communicated with the front end of the accommodating cavity of the movement assembly through a fifth air passage, and the fifth air passage is communicated with the second air inlet.

[0027] Preferably, a kidney-shaped hole is provided on the front end cover, and further includes a front locking bolt passing through the kidney-shaped hole and connected to the front locking slider.

[0028] The present invention is provided with a second movement assembly inside the first movement assembly, that is, a movable rod is arranged inside the piston rod, and a second locking assembly for locking the second movement assembly is provided at the rear end of the rear end cover. When the first section extends to the end of the movable rod, after the second movement assembly is unlocked, the second section extends completely. The first movement assembly can also be locked, which is used in the fire door and window industry. Locking the first movement assembly can prevent the doors and windows from being blown open by the wind. A front retraction assembly can also be provided at the front end to lock the fully extended piston rod and prevent the doors and windows from being blown closed by the wind. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the present invention;

[0030] Figure 2 is a schematic structural diagram of the first movement assembly of the present invention;

[0031] Figure 3 It is a schematic structural diagram of the second moving component of the present invention;

[0032] Figure 4 It is a schematic structural diagram of the first locking component and the second locking component at the rear end of the present invention;

[0033] Figure 5 It is a schematic structural diagram of the front retracting component at the front end of the present invention;

[0034] Figure 6 It is a state diagram when the first moving component and the second moving component of the present invention are locked simultaneously;

[0035] Figure 7 It is a state diagram when the first moving component of the present invention is unlocked and the second moving component is locked;

[0036] Figure 8 It is a state diagram when the first moving component and the second moving component of the present invention are unlocked simultaneously;

[0037] Figure 9 It is a state diagram when the front locking component of the present invention is unlocked.

[0038] In the figure: 1 - cylinder block; 2 - front end cover; 2.1 - front sealing cover; 2.2 - fifth air passage; 3 - rear end cover; 3.1 - first rear accommodating cavity; 3.2 - first rear sealing cover; 3.3 - first air passage; 4 - moving component accommodating cavity;

[0039] 5 - first moving component; 5.1 - piston; 5.2 - piston rod; 5.3 - adapter; 5.4 - lifting eye bolt; 5.5 - first locking pin; 5.6 - first limiting end face; 5.7 - first locking groove; 5.8 - front locking groove;

[0040] 6 - second moving component; 6.1 - movable rod; 6.2 - second locking pin; 6.3 - second limiting end face; 6.4 - limiting protrusion; 6.5 - second locking groove;

[0041] 7 - first locking component; 7.1 - first limiting steel ball; 7.2 - first rear locking slider; 7.3 - first rear locking slider return spring; 7.4 - first steel ball support plug; 7.5 - first steel ball support plug return spring; 7.6 - first steel ball support plug accommodating cavity;

[0042] 8 - second locking component; 8.1 - second limiting steel ball; 8.2 - second rear locking slider; 8.3 - second rear locking slider return spring; 8.4 - second steel ball support plug; 8.5 - second steel ball support plug return spring; 8.6 - second steel ball support plug accommodating cavity;

[0043] 9 - front locking component; 9.1 - front locking slider; 9.2 - front locking steel ball; 9.3 - front locking slider return spring; 9.4 - front locking bolt;

[0044] 10 - Second locking component housing; 10.1 - Second rear accommodation cavity; 10.2 - Second rear cover; 10.3 - Third air passage; 10.4 - Fourth air passage;

[0045] 11 - High - pressure opening valve; 11.1 - Valve body; 11.2 - High - pressure valve piston; 11.3 - High - pressure valve return spring; 11.4 - High - pressure valve piston accommodation cavity; 11.5 - Pressure relief hole;

[0046] 12 - Second air passage. Specific implementation manner

[0047] The present invention provides a two - stage cylinder with two - stage stroke.

[0048] It includes a cylinder block 1, a front end cover 2 is arranged at the front end of the cylinder block 1, a rear end cover 3 is arranged at the rear end of the cylinder block 1, a moving component accommodation cavity 4 is arranged inside the cylinder block 1, a first moving component 5 moving along the axial direction of the cylinder block is arranged inside the moving component accommodation cavity 4, and a first locking component 7 matching with the first moving component 5 is arranged on the rear end cover 2. A second moving component 6 is movably connected inside the first moving component 5, and a second locking component 8 matching with the second moving component 6 is arranged at the rear end of the first locking component 7. The first locking component 7 unlocks the first moving component 5, the first moving component 5 moves forward to the front end of the second moving component 6 (at this time, the second moving component is locked by the second locking component), the second locking component 8 unlocks the second moving component 6, and the second moving component 6 moves forward together with the first moving component 5 until the first moving component 5 abuts against the front end cover 2.

[0049] Locking components can be provided for both the first moving component and the second moving component for locking and unlocking, or a locking component can be provided only for the second moving component. If the present invention is applied to fire - fighting doors and windows, strong winds may blow the doors and windows open, so when the doors and windows are closed, the first moving component also needs to be locked, and usually two locking components are provided.

[0050] Such as Figure 2As shown, the first operating component 5 includes a piston 5.1 and a piston rod 5.2. The rear end of the piston rod 5.2 is connected to the piston 5.1. The piston 5.1 is located within the accommodation cavity 4 of the moving component and can perform axial reciprocating motion along the cylinder block 1. The front end of the piston rod 5.2 extends outside the front end cover 2. The front end of the piston rod 5.2 is connected with a lifting eye bolt 5.4 through an adapter 5.3. A first locking pin 5.5 is provided at the rear end of the piston rod 5.2. The first locking pin 5.5 can be integrally formed with the piston rod 5.2 or can adopt a split design. For the convenience of processing, the split design is adopted in this embodiment. Both the piston rod 5.2 and the first locking pin 5.5 are of hollow structure. Since the inner diameter of the first locking pin 5.5 is smaller than that of the piston rod, a first limiting end face 5.6 is formed at the front end of the first locking pin 5.5. A first locking groove 5.7 is provided on the outer periphery of the rear end of the first locking pin 5.5. A front locking groove 5.8 is provided on the outer periphery of the rear part of the piston rod 5.2.

[0051] As Figure 3 shown, the second moving component 6 includes a movable rod 6.1. A second locking pin 6.2 is provided at the rear end of the movable rod 6.1. The second locking pin 6.2 can be integrally formed with the movable rod 6.1 or can adopt a split design. For the convenience of processing, the split design is adopted in this embodiment. The outer diameter of the second locking pin 6.2 is larger than that of the movable rod 6.1, so a second limiting end face 6.3 is formed at the front end of the second locking pin. The movable rod 6.1 is arranged in the hollow inner cavities of the piston rod 5.2 and the first locking pin 5.5. A limiting protrusion 6.4 is provided at the front end of the movable rod 6.1. When the movable rod 6.1 moves away from the piston rod 5.2, when the limiting protrusion 6.4 abuts against the first limiting end face 5.6, the two rods extend to the longest. When the movable rod 6.1 moves towards the piston rod 5.2, when the rear end face of the first locking pin 5.5 abuts against the second limiting end face 6.3, the two rods shrink to the shortest. The outer diameter of the movable rod 6.1 matches the inner diameter of the first locking pin 5.5, so that there is a certain frictional force between the movable rod and the first locking pin, and a certain force is required to make the two move relative to each other. A second locking groove 6.5 is provided on the outer periphery of the rear end of the second locking pin 6.2.

[0052] As Figure 4As shown in the figure, a first rear accommodation cavity 3.1 is provided at the rear end of the rear end cover 3. The first locking assembly 7 is installed in the first rear accommodation cavity 3.1 and includes a first limiting steel ball 7.1, a first rear locking slider 7.2, a first rear locking slider return spring 7.3, a first steel ball support plug 7.4, and a first steel ball support plug return spring 7.5. The first rear locking slider 7.2 can move back and forth in the first rear accommodation cavity 3.1. A first steel ball support plug accommodation cavity 7.6 is provided on the inner side of the front end of the first rear locking slider 7.2. The first steel ball support plug 7.4 is arranged in the first steel ball support plug accommodation cavity 7.6. A first steel ball support plug return spring 7.5 is provided between the first steel ball support plug 7.4 and the first rear locking slider 7.2. A first steel ball accommodation groove is provided at the front end of the first steel ball support plug accommodation cavity 7.6, and an inclined surface is provided at the front end of the first steel ball accommodation groove. The first limiting steel ball 7.1 is located in the first steel ball accommodation groove. The inclined surface is provided to make it easy for the first limiting steel ball to enter and exit the first steel ball accommodation groove. When locking, a part of the first limiting steel ball will be stuck in the first locking groove. A first rear cover 3.2 is installed at the rear end of the rear end cover 3. The first rear locking slider return spring 7.3 is arranged between the first rear cover 3.2 and the first rear locking slider 7.2. A first air passage 3.3 is provided on the rear end cover 3 to communicate the rear end of the moving component accommodation cavity 4 with the front end of the first rear accommodation cavity 3.1. The rear end of the moving component accommodation cavity 4 is communicated with the first air inlet through the air passage. The first air inlet can be opened on the rear end cover, or on the cylinder block or the front end cover. A sealing ring is provided between the first rear locking slider 7.2 and the inner wall of the rear end cover 3.

[0053] The rear end of the first rear locking slider 7.2 extends out of the rear end cover 3. A second locking component housing 10 is fixedly connected to the rear end of the first rear locking slider 7.2. A second rear accommodation cavity 10.1 is provided at the rear end of the second locking component housing 10. The second locking component 8 is installed in the second rear accommodation cavity 10.1. The second locking component 8 includes a second limiting steel ball 8.1, a second rear locking slider 8.2, a second rear locking slider return spring 8.3, a second steel ball support plug 8.4, and a second steel ball support plug return spring 8.5. The second rear locking slider 8.2 can move back and forth in the second rear accommodation cavity 10.1. A second steel ball support plug accommodation cavity 8.6 with an opening facing forward is formed in the second rear locking slider 8.2. The second steel ball support plug 8.4 is arranged in the second steel ball support plug accommodation cavity 8.6. A second steel ball support plug return spring 8.5 is provided between the second steel ball support plug 8.4 and the second rear locking slider 8.2. A second steel ball accommodation groove is provided at the front end of the second steel ball support plug accommodation cavity 8.6. An inclined surface is provided at the front end of the second steel ball accommodation groove. The second limiting steel ball 8.1 is located in the second steel ball accommodation groove. The inclined surface is provided to make it easy for the second limiting steel ball to enter and exit the second steel ball accommodation groove. When locking, a part of the second limiting steel ball will be stuck in the second locking groove. A second rear cover 10.2 is installed at the rear end of the second locking component housing 10. The second rear locking slider return spring 8.3 is arranged between the second rear cover 10.2 and the second rear locking slider 8.2. A sealing ring is provided between the second rear locking slider 8.2 and the second locking component housing 10. A high-pressure opening valve 11 is also installed on the second locking component housing 10, including a valve body 11.1, a high-pressure valve piston 11.2, and a high-pressure valve return spring 11.3. A high-pressure valve piston accommodation cavity 11.4 is provided in the valve body 11.1. A sealing ring is provided between the outer periphery of the high-pressure valve piston and the valve body. A high-pressure valve return spring 11.3 is provided between the high-pressure valve piston 11.2 and the rear end of the high-pressure valve piston accommodation cavity 11.4. A pressure relief hole 11.5 communicating with the outside is provided at the rear end of the high-pressure valve piston accommodation cavity 11.4. A second air passage 12 communicating the front end of the high-pressure valve piston accommodation cavity 11.4 with the first accommodation cavity 3.1 is provided on the first rear locking slider 7.2, the second locking component housing 10, and the valve body. A third air passage 10.3 communicating the front end of the high-pressure valve piston accommodation cavity 11.4 with the second rear accommodation cavity 10.1 is provided on the second locking component housing 10. A fourth air passage 10.4 communicating the rear end of the high-pressure valve piston accommodation cavity 11.4 with the second rear accommodation cavity 10.1 is also provided on the second locking component housing 10. The second locking component housing 10 and the first rear locking slider 7.2 are provided as hollow structures, and are provided with through holes for the second locking pin 6.5 at the rear end of the movable rod to pass through. A sealing ring is provided between the rear end surface of the first rear locking slider 7.2 and the second locking component housing 10. The inner diameter of the sealing ring matches the outer diameter of the second locking pin. When the second moving component is locked, it prevents gas from entering the second rear accommodation cavity from the first accommodation cavity through the gap between the outer diameter of the second locking pin and the inner wall of the first rear locking slider.

[0054] When the gas in the first rear accommodation cavity enters the front end of the high-pressure valve piston accommodation cavity 11.4 through the second air passage 12, and the gas pressure is greater than the acting force of the high-pressure valve return spring, the gas pushes the high-pressure valve piston to move backward, so that the second air passage, the front end of the high-pressure valve piston accommodation cavity, and the third air passage 10.3 are connected. The high-pressure valve piston 11.2 blocks the fourth air passage 10.4, and the gas in the second rear accommodation cavity 10.1 cannot overflow through the fourth air passage via the pressure relief hole 11.5. If the gas pressure is less than the acting force of the high-pressure valve return spring, the high-pressure valve return spring 11.3 pushes the high-pressure valve piston to reset. The high-pressure valve piston blocks the third air passage 10.3, and the gas cannot enter the second rear accommodation cavity. The second rear accommodation cavity is connected to the pressure relief hole through the fourth air passage.

[0055] As Figure 5 , 9 shown, a front accommodation cavity is provided at the front end of the front end cover 2. The front locking assembly 9 is installed in the front accommodation cavity and includes a front lock slider 9.1, front lock steel balls 9.2, and a front lock slider return spring 9.3. A front seal cover 2.1 is provided at the front end of the front end cover 2, and the front lock slider return spring 9.3 is arranged between the front seal cover 2.1 and the front lock slider 9.1. A front lock steel ball accommodation groove is provided on the inner side of the rear end of the front lock slider 9.1. A front lock bolt 9.4 extending outside the front end cover is also connected to the front lock slider 9.1, and a kidney-shaped hole for the front lock bolt 9.4 to move back and forth is provided on the front end cover 9.1. Thus, the front lock slider can be manually pushed through the front lock bolt, so that the front lock steel balls are disengaged from the front lock groove 5.8 to unlock the piston rod. The front lock steel balls 9.2 are matched with the front lock groove 5.8 on the piston rod 5.2. The front accommodation cavity is connected to the front end of the moving component accommodation cavity 4 through a fifth air passage 2.2, and the fifth air passage 2.2 is connected to the second air inlet, and the second air inlet is provided on the front end cover.

[0056] The piston 5.1 divides the moving component accommodation cavity 4 into two parts, front and rear. The high-pressure valve piston 11.2 divides the high-pressure valve piston accommodation into two parts, front and rear. The two parts are opposite, and as the piston 5.1 and the high-pressure valve piston 11.2 move, the area will change.

[0057] Now in combination with Figure 6 , 7 , 8, the working principle of the two-stage cylinder will be described.

[0058] Contraction state: As Figure 6As shown, the first limit steel ball 7.1 is located in the first lock groove 5.7 of the first lock pin 5.5. The first rear lock slider 7.2 abuts against the front wall of the first rear accommodation cavity under the action of the first rear lock slider return spring 7.3, and restricts the first limit steel ball 7.1 from sliding out of the first lock groove 5.7, thereby locking the first moving component. The first steel ball support plug 7.4 abuts against the rear end of the first lock pin 5.5 under the action of the first steel ball support plug return spring 7.5. The second limit steel ball 8.1 is located in the second lock groove of the second lock pin 6.2. The second rear lock slider 8.2 abuts against the front wall of the second rear accommodation cavity under the action of the second rear lock slider return spring 8.3, and restricts the second limit steel ball 8.1 from sliding out of the second lock groove, thereby locking the second moving component. The second steel ball support plug 8.4 abuts against the rear end of the second lock pin 6.2 under the action of the second steel ball support plug return spring 8.5.

[0059] Unlocking of the first moving component: As Figure 6 , 7 shown, compressed gas at 7 bar enters through the first air inlet communicating with the rear end of the moving component accommodation cavity 4, and the compressed gas enters the first rear accommodation cavity 3.1 through the first air passage 3.3, pushing the first rear lock slider 7.2 backward, thereby releasing the restriction on the first limit steel ball 7.1, which slides out of the first lock groove 5.7. After the first moving component is unlocked, the compressed gas pushes the piston 5.1, causing the first moving component to move forward. At the same time, the first steel ball support plug 7.4 moves forward under the action of the first steel ball support plug return spring 7.5 until it abuts against the first limit steel ball 7.1, restricting the first limit steel ball 7.1 within the space enclosed by the first steel ball support plug 7.4, the front wall of the first rear accommodation cavity, and the first rear lock slider 7.2, preventing the first limit steel ball 7.1 from falling into the middle and losing its limiting function. The first moving component moves forward until the first limit end face 5.6 at the front end of the first lock pin 5.5 abuts against the limit protrusion 6.4 at the front end of the movable rod 6.1. The first stroke of the piston rod extends. At this time, the compressed gas at 7 bar is not sufficient to overcome the acting force of the high-pressure valve piston return spring to push the high-pressure valve piston, and the second moving component remains locked.

[0060] Unlocking of the second moving component: As Figure 7 , 8As shown, compressed gas at 10 bar enters through the first air inlet communicating with the rear end of the moving component accommodation cavity. The compressed gas enters the first rear accommodation cavity 3.1 through the first air passage 3.3, and then reaches the front end of the high-pressure valve piston accommodation cavity through the second air passage 12, pushing the high-pressure valve piston 11.2 backward (the high-pressure valve piston requires high-pressure gas above 10 bar to be pushed open, so the compressed gas at 7 bar cannot push it). The compressed gas enters the second rear accommodation cavity through the third air passage 10.3, thereby pushing the second rear locking slider 8.2 backward, thus releasing the restriction on the second limiting steel ball 8.1 and sliding out of the second locking groove. After the second moving component is unlocked, the compressed gas pushes the first moving component and then drives the second moving component forward. At the same time, the second steel ball support plug 8.4 moves forward under the action of the second steel ball support plug return spring 8.5 until it abuts against the second limiting steel ball 8.1, restricting the second limiting steel ball 8.1 within the space enclosed by the second steel ball support plug 8.4, the front wall of the second rear accommodation cavity, and the second rear locking slider 8.2, preventing the second limiting steel ball from falling into the middle and losing its limiting function. The first moving component moves forward until the piston 5.1 abuts against the front wall of the moving component accommodation cavity, achieving the extension of the second stroke of the piston rod.

[0061] Piston rod locking: When the piston rod is fully extended, the front locking steel ball 9.2 sinks into the front locking groove 5.8 of the piston rod, locking the piston rod.

[0062] Piston rod and movable rod contraction and reset: Compressed gas at 7 bar enters through the second air inlet communicating with the fifth air passage 2.2. The first air inlet communicating with the rear end of the moving component accommodation cavity starts to release pressure. The high-pressure valve piston of the high-pressure opening valve resets under the action of the high-pressure valve piston return spring, isolating the second air passage from the third air passage. The gas in the second rear accommodation cavity is released through the fourth air passage 10.4, the high-pressure valve piston accommodation cavity, and the pressure relief hole 11.5. As Figure 9 shown, the compressed gas enters the front accommodation cavity through the fifth air passage 2.2, pushing the front locking slider 9.1 forward, releasing the restriction on the front locking steel ball 9.2, and the front locking steel ball slides out of the front locking groove. The piston rod 5.2 moves backward with the piston 5.1 under the action of the compressed gas, driving the movable rod backward at the same time. As Figure 8 shown, the second locking pin 6.2 of the second moving component passes through the central through holes of the rear end cover, the first rear locking slider, and the second locking component housing, abuts against the second steel ball support plug 8.4 and pushes the second steel ball support plug 8.4 backward until the second limiting steel ball 8.1 sinks into the second locking groove on the second locking pin. The second rear locking slider 8.2 resets under the action of the second rear locking slider return spring 8.3, thereby locking the second moving component by limiting the second limiting steel ball within the second locking groove. Figure 7As shown in the figure, after the second moving component is locked, the first moving component continues to move backward. The first locking pin 5.5 passes through the central through hole of the rear end cover and abuts against the first steel ball support plug 7.4, pushing the first steel ball support plug 7.4 to move backward until the first limiting steel ball 7.1 falls into the first locking groove on the first locking pin 5.5. The first rear locking slider 7.2 is reset under the action of the first rear locking slider return spring 7.3, so that the first limiting steel ball is limited in the first locking groove to lock the first moving component.

[0063] In the above embodiments, locking components are provided for both the first moving component and the second moving component. When it is not necessary to lock the first moving component, the second locking component can be installed on the rear end cover, that is, the second rear accommodating cavity is arranged at the position of the first rear accommodating cavity. In the above embodiments, a high-pressure opening valve is provided, or it can be not provided. In this case, the two moving components are unlocked simultaneously, or gas corresponding to the pressure for opening the high-pressure opening valve can be directly introduced. In the above embodiments, the moving component accommodating cavity, the first rear accommodating cavity, and the second accommodating cavity are connected through an air passage to achieve synchronous control of one air source, or multiple air sources can be provided for separate control. The first locking component and the second locking component can also adopt other existing locking devices. For example, an interference fit method can be adopted, and a slot is provided at the rear end, and unlocking can only occur when the piston driving force is greater than the frictional force.

Claims

1. A two-stage cylinder, comprising a cylinder block, wherein a moving component accommodating cavity is arranged inside the cylinder block, and is characterized in that: A first moving component and a second moving component are arranged in the accommodating cavity of the moving component; the first moving component includes a piston rod and a piston for driving the piston rod to move axially along the cylinder body; the second moving component includes a movable rod, the piston rod is of a hollow structure, and the front end of the movable rod is movably arranged in the piston rod; a locking device for locking the movable rod is arranged at the rear end of the cylinder body. When the movable rod is locked, the piston rod moves forward until the rear end of the piston rod moves forward to the front end of the movable rod, and the piston rod extends to the first stroke. When the movable rod is unlocked, the piston rod drives the movable rod to move forward until the piston abuts against the front wall of the accommodating cavity of the moving component, and the piston rod extends to the second stroke; A second rear accommodating cavity is arranged at the rear end of the cylinder body, the locking device is a second locking component, and the second locking component is arranged in the second rear accommodating cavity; the second locking component is used for locking or unlocking the movable rod; a first rear accommodating cavity is further arranged at the rear end of the cylinder body in front of the second rear accommodating cavity, and a first locking component is installed in the first rear accommodating cavity; the first locking component is used for locking or unlocking the piston rod; A high-pressure opening valve is installed on the housing of the second locking component. The high-pressure opening valve includes a valve body, a high-pressure valve piston, and a high-pressure valve return spring. A high-pressure valve piston accommodating cavity with a pressure relief hole is formed in the valve body. The high-pressure valve piston is arranged in the high-pressure valve piston accommodating cavity and divides the high-pressure valve piston accommodating cavity into front and rear parts; the high-pressure valve piston accommodating cavity is communicated with the first rear accommodating cavity and the second rear accommodating cavity through a second air passage and a third air passage respectively, and the high-pressure valve piston accommodating cavity is further communicated with the second rear accommodating cavity through a fourth air passage.

2. The two-stage cylinder according to claim 1, wherein: A second locking pin is arranged at the rear end of the movable rod, and a second locking groove is arranged on the outer wall of the rear end of the second locking pin; The second locking component includes a second limiting steel ball, a second rear locking slider, a second rear locking slider return spring, a second steel ball support plug, and a second steel ball support plug return spring; the second rear locking slider is movably arranged in the second rear accommodating cavity, and the second rear locking slider return spring is used to urge the second rear locking slider to move forward and reset; a second steel ball support plug accommodating cavity is arranged at the front end of the second rear locking slider, the second steel ball support plug is arranged in the second steel ball support plug accommodating cavity, and the second steel ball support plug return spring is used to urge the second steel ball support plug to move forward and reset; the second limiting steel ball is arranged close to the front wall of the second rear accommodating cavity; When the second locking assembly locks the movable rod, the second locking pin presses the second steel ball support plug backward, and the second limiting steel ball snaps into the second locking groove; when the second locking assembly unlocks the movable rod, the gas entering the second rear accommodation cavity pushes the second rear locking slider backward, the second limiting steel ball disengages from the second locking groove, the second steel ball support plug resets under the action of the second steel ball support plug return spring, and the second limiting steel ball is restricted in the space formed by the second steel ball support plug, the second rear locking slider and the inner wall of the second rear accommodation cavity.

3. The two-stage cylinder according to claim 2, wherein: When the second locking assembly locks the movable rod, the gas pressure in the second rear accommodation cavity is less than the acting force of the second rear locking slider return spring, and the second rear locking slider abuts against the front wall of the second rear accommodation cavity under the action of the second rear locking slider return spring, restricting the second limiting steel ball from disengaging from the second locking groove.

4. The two-stage cylinder according to claim 2, wherein: A first locking pin is provided at the rear end of the piston rod, and a first locking groove is provided on the outer wall of the rear end of the first locking pin; The first locking assembly includes a first limiting steel ball, a first rear locking slider, a first rear locking slider return spring, a first steel ball support plug, and a first steel ball support plug return spring; the first rear locking slider is movably arranged in the first rear accommodation cavity, and the first rear locking slider return spring is used to urge the first rear locking slider to move forward and reset; a first steel ball support plug accommodation cavity is provided at the front end of the first rear locking slider, the first steel ball support plug is arranged in the first steel ball support plug accommodation cavity, and the first steel ball support plug return spring is used to urge the first steel ball support plug to move forward and reset; the first limiting steel ball is arranged near the front wall of the first rear accommodation cavity; When the first locking assembly locks the piston rod, the first locking pin presses the first steel ball support plug backward, and the first limiting steel ball snaps into the first locking groove; when the first locking assembly unlocks the piston rod, the gas entering the first rear accommodation cavity pushes the first rear locking slider backward, the first limiting steel ball disengages from the first locking groove, the first steel ball support plug resets under the action of the first steel ball support plug return spring, and the first limiting steel ball is restricted in the space formed by the first steel ball support plug, the first rear locking slider and the inner wall of the first rear accommodation cavity.

5. The two-stage cylinder according to claim 4, characterized in that: When the first locking assembly locks the piston rod, the gas pressure in the first rear accommodation cavity is less than the acting force of the first rear locking slider return spring, and the first rear locking slider abuts against the front wall of the first rear accommodation cavity under the action of the first rear locking slider return spring, restricting the first limiting steel ball from disengaging from the first locking groove.

6. The two-stage cylinder according to any one of claims 1-4, characterized in that: When the second locking assembly locks the movable rod, the first rear accommodation cavity is depressurized. The high-pressure valve piston is reset under the action of the high-pressure valve return spring. The high-pressure valve piston separates the second air passage and the third air passage. The fourth air passage, the rear part of the high-pressure valve piston accommodation cavity, and the pressure relief hole are communicated. The second rear accommodation cavity is depressurized through the fourth air passage, the high-pressure valve piston accommodation cavity, and the pressure relief hole. When the second locking assembly unlocks the movable rod, the gas pressure entering the front part of the high-pressure valve piston accommodation cavity from the first rear accommodation cavity through the second air passage is greater than the acting force of the high-pressure valve return spring, so that the second air passage, the front part of the high-pressure valve piston accommodation cavity, and the third air passage are communicated, and the high-pressure valve piston blocks the fourth air passage.

7. The two-stage cylinder according to claim 6, characterized in that: The movement assembly accommodation cavity is separated into front and rear parts by the piston; the first rear accommodation cavity is communicated with the first air inlet through the first air passage and the rear part of the movement assembly accommodation cavity.

8. The two-stage cylinder according to claim 4, wherein: When the second locking assembly locks the movable rod, the first rear accommodation cavity is depressurized. The high-pressure valve piston is reset under the action of the high-pressure valve return spring. The high-pressure valve piston separates the second air passage and the third air passage. The fourth air passage, the rear part of the high-pressure valve piston accommodation cavity, and the pressure relief hole are communicated. The second rear accommodation cavity is depressurized through the fourth air passage, the high-pressure valve piston accommodation cavity, and the pressure relief hole. When the second locking assembly unlocks the movable rod, the gas pressure entering the front part of the high-pressure valve piston accommodation cavity from the first rear accommodation cavity through the second air passage is greater than the acting force of the high-pressure valve return spring, so that the second air passage, the front part of the high-pressure valve piston accommodation cavity, and the third air passage are communicated, and the high-pressure valve piston blocks the fourth air passage. The movement assembly accommodation cavity is separated into front and rear parts by the piston; the first rear accommodation cavity is communicated with the first air inlet through the first air passage and the rear part of the movement assembly accommodation cavity. When unlocking, the piston rod is unlocked before the movable rod, that is, the gas pressure introduced into the first air inlet is greater than the acting force of the first rear lock slider return spring, so as to unlock the piston rod, and then pressurize until the air pressure is greater than the acting force of the high-pressure valve return spring, so as to unlock the movable rod.

9. The two-stage cylinder according to claim 4, wherein: A first steel ball accommodation groove for placing the first limiting steel ball is arranged at the front end of the first rear accommodation cavity. An inclined surface facilitating the first limiting steel ball to enter and exit the first steel ball accommodation groove is arranged at the front end of the first steel ball accommodation groove; and / or, a second steel ball accommodation groove for placing the second limiting steel ball is arranged at the front end of the second rear accommodation cavity. An inclined surface facilitating the second limiting steel ball to enter and exit the second steel ball accommodation groove is arranged at the front end of the second steel ball accommodation groove.

10. The two-stage cylinder according to claim 4, characterized in that: The first rear accommodation cavity is arranged on the rear end cover at the rear end of the cylinder block. The rear end of the first rear lock slider extends out of the rear end cover. A second locking assembly housing is installed at the rear end of the first rear lock slider. The second rear accommodation cavity is arranged at the rear end of the second locking assembly housing.

11. The two-stage cylinder according to claim 10, wherein: A sealing ring is arranged between the first rear lock slider and the second locking assembly housing.

12. The two-stage cylinder according to claim 10, characterized in that: The inner diameter of the first locking pin is smaller than the inner diameter of the piston rod, so as to form a first limiting end face at the front end of the first locking pin, and a limiting protrusion matching with the first limiting end face is arranged at the front end of the movable rod; the outer diameter of the second locking pin is larger than the outer diameter of the movable rod, so as to form a second limiting end face at the front end of the second locking pin, and the second limiting end face is matched with the rear end face of the first locking pin.

13. The two-stage cylinder according to claim 12, characterized in that: The outer diameter of the movable rod matches the inner diameter of the first locking pin. When the external force is less than the frictional force between the two, the two move together. When the external force is greater than the frictional force between the two, the two can move relative to each other.

14. The two-stage cylinder according to any one of claims 1-4, characterized in that: A front locking groove is arranged on the piston rod; a front accommodating cavity is arranged on the front end cover at the front end of the cylinder block, and a front locking component is installed in the front accommodating cavity; the front locking component includes a front locking slider, a front locking steel ball, and a front locking slider return spring; The front locking slider is arranged in the front accommodating cavity so as to be movable back and forth, and the front locking slider return spring is used to urge the front locking slider to move backward and reset; the front locking steel ball is arranged close to the rear wall of the front accommodating cavity; when the front locking component locks the piston rod, the front locking steel ball is stuck into the front locking groove; when the front locking component unlocks the piston rod, the gas entering the front accommodating cavity pushes the front locking slider to move forward, and the front locking steel ball disengages from the front locking groove.

15. The two-stage cylinder according to claim 14, wherein: The front accommodating cavity is communicated with the front end of the accommodating cavity of the motion component through a fifth air passage, and the fifth air passage is communicated with the second air inlet.

16. The two-stage cylinder according to claim 14, wherein: A kidney-shaped hole is arranged on the front end cover, and a front locking bolt passing through the kidney-shaped hole and connected with the front locking slider is further included.

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