A control circuit of hydraulic quick-change device for excavator

Abstract

The present invention discloses a control circuit of a hydraulic quick-change device for an excavator, comprising: a quick-change oil cylinder, which comprises a rod chamber and a rodless chamber; a first reversing valve, which is used to switch the oil inlet between the rod chamber and the rodless chamber, the first reversing valve is connected to the rod chamber through a rod chamber oil circuit, and is connected to the rodless chamber through a rodless chamber oil circuit; a load-sensitive pump, which is used to provide a hydraulic source for the boom action of the excavator; a first hydraulic source, which has hydraulic oil with a stable pressure; a shuttle valve, whose two oil inlets are respectively connected to the oil outlet of the load-sensitive pump and the first hydraulic source, and the oil outlet of the shuttle valve and the oil inlet of the first reversing valve are connected through the first oil inlet circuit. By introducing the first hydraulic source and under the selection of the shuttle valve, it can be ensured that the first oil inlet circuit has an oil source pressure at least not lower than that of the first hydraulic source and is output to the quick-change oil cylinder, which is beneficial to maintaining the pressure of the rodless chamber of the quick-change oil cylinder, and at the same time, compared with the prior art, it can avoid the load-sensitive pump and the engine from being continuously loaded.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control of engineering machinery, and more specifically to a control circuit of a hydraulic quick-change device for an excavator. Background Art

[0002] For excavators, it is usually necessary to replace the bucket or other accessories according to different working conditions. Currently, the bucket or other accessories are mainly replaced through hydraulic quick-change devices.

[0003] The hydraulic quick-change device includes a cylinder and a hydraulic circuit for controlling the movement of the cylinder, so as to control the extension and retraction of the cylinder through the hydraulic circuit, thereby achieving the tightening or loosening of the bucket or other accessories. When the excavator is started, it is necessary to ensure that the rodless chamber of the cylinder of the hydraulic quick-change device is filled with high-pressure oil and maintained at a high pressure, so that the piston rod of the cylinder is extended, thereby locking the bucket or other accessories to prevent them from falling during the operation of the excavator; when the bucket or other accessories need to be replaced, it is necessary to fill the rod chamber of the cylinder of the hydraulic quick-change device with oil, so that the piston rod of the cylinder is retracted, so as to loosen the bucket or other accessories, so that the bucket or other accessories can be replaced.

[0004] In the prior art, the hydraulic circuit of the hydraulic quick-change device mainly uses the main pump of the excavator to supply oil to the oil cylinder of the hydraulic quick-change device, and uses a conventional reversing valve to switch the oil supply of the rod chamber and the rodless chamber of the oil cylinder. Or directly use the pilot oil source to supply oil, and use the reversing valve to switch the oil supply of the rod chamber and the rodless chamber of the oil cylinder.

[0005] However, in order to achieve continuous pressure maintenance in the rodless chamber of the hydraulic cylinder of the hydraulic quick-change device during the start-up and operation of the excavator, the main pump and engine of the excavator will be continuously loaded. Otherwise, the rodless chamber of the cylinder cannot be continuously pressurized, which may cause the bucket or other accessories to fall. For the hydraulic quick-change circuit that directly uses the pilot oil source, it is usually not suitable for most hydraulic quick-change devices due to insufficient oil supply pressure, such as insufficient tightening pressure of the hydraulic quick-change device, or the inability to open the hydraulic quick-change device when replacing the bucket or accessories.

[0006] In summary, how to prevent the bucket or other accessories from falling without the main pump and engine of the excavator being continuously loaded, while ensuring that the hydraulic quick-change device opens normally, is a problem that urgently needs to be solved by technical personnel in this field. Summary of the invention

[0007] In view of this, an object of the present invention is to provide a control circuit for a hydraulic quick-change device for an excavator, so as to prevent the bucket or other accessories from falling and ensure that the hydraulic quick-change device opens normally without the need for the main pump and engine of the excavator to be continuously loaded.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A control circuit of a hydraulic quick-change device for an excavator, comprising:

[0010] A quick-change cylinder including a rod chamber and a rodless chamber;

[0011] a first reversing valve, which is used to switch the oil inlet between the rod chamber and the rodless chamber, the first reversing valve being connected to the rod chamber through a rod chamber oil passage and connected to the rodless chamber through a rodless chamber oil passage;

[0012] A load sensing pump, which is used to provide a hydraulic source for the boom action of the excavator;

[0013] A first hydraulic source having hydraulic oil at a stable pressure;

[0014] The shuttle valve has two oil inlets connected to the oil outlet of the load sensing pump and the first hydraulic source respectively, and the oil outlet of the shuttle valve and the oil inlet of the first reversing valve are connected through a first oil inlet path.

[0015] Preferably, the first oil inlet circuit or the rodless chamber oil circuit is provided with a pressure reducing valve.

[0016] Preferably, a pressure feedback oil circuit is provided between the first reversing valve and the load-sensitive pump, and the pressure feedback oil circuit is provided with a switch valve. The switch valve and the first reversing valve are energized and de-energized at the same time, so that when the first reversing valve is actuated and the oil inlet of the quick-change cylinder changes from the rodless chamber to the rod chamber, the switch valve is opened to feed back the pressure in the rod chamber to the load-sensitive pump through the pressure feedback oil circuit.

[0017] Preferably, a first throttling damper is provided between the intersection of the pressure feedback oil circuit and the first oil inlet circuit and the shuttle valve.

[0018] Preferably, the first oil inlet circuit and the pressure feedback oil circuit are respectively provided with a one-way valve.

[0019] Preferably, the shuttle valve, the pressure reducing valve, the first throttling damper, the first reversing valve, the switch valve and the one-way valve are integrated into a valve link.

[0020] Preferably, the pressure cut-off valve of the load-sensitive pump is provided with an external control port, and the external control port is connected to a pilot control valve group, the pilot control valve group includes a hydraulic oil circuit and an oil return circuit arranged in parallel, the hydraulic oil circuit is provided with a second throttling damper and a pilot control valve connected in series, the oil inlet of the pilot control valve is connected to a second hydraulic source, the second hydraulic source has hydraulic oil with a stable pressure, the oil return port of the pilot control valve is connected to the oil return circuit, and the oil return circuit is provided with a third throttling damper.

[0021] Preferably, the first hydraulic source and the second hydraulic source are the same hydraulic source.

[0022] Preferably, the pilot control valve is an electric proportional pressure reducing valve, an electrically controlled two-position three-way switching valve or a hydraulically controlled two-position three-way switching valve.

[0023] Preferably, it also includes a hydraulic lock for locking the rod chamber oil circuit and the rodless chamber oil circuit respectively.

[0024] The hydraulic quick-change device control circuit for an excavator provided by the present invention can ensure that the first oil inlet circuit has an oil source pressure at least not lower than that of the first hydraulic source and outputs it to the quick-change cylinder under the selection action of the shuttle valve, which is beneficial to maintaining the pressure of the rodless chamber of the quick-change cylinder. At the same time, compared with the prior art, it can avoid continuous loading of the load-sensitive pump and the engine.

[0025] In addition, when it is necessary to replace the bucket or other accessories, the first reversing valve is switched. Under the action of the shuttle valve, the first hydraulic source or load-sensitive pump can supply oil to the rod chamber of the quick-change cylinder, ensuring that the first oil inlet circuit has an oil source pressure at least not lower than that of the first hydraulic source and outputs it to the quick-change cylinder, so that the quick-change cylinder can be unlocked using high pressure to ensure that the bucket or other accessories can be smoothly detached. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 A control principle diagram of a control circuit of a hydraulic quick-change device for an excavator provided in a first specific embodiment of the present invention;

[0028] Figure 2 A control principle diagram of a control circuit of a hydraulic quick-change device for an excavator provided in a second specific embodiment of the present invention;

[0029] Figure 3 This is a control principle diagram of a control circuit of a hydraulic quick-change device for an excavator provided in a third specific embodiment of the present invention.

[0030] Figures 1 to 3 The reference numerals in the figures are as follows:

[0031] 1 is a quick-change cylinder, 2 is the first reversing valve, 3 is a load-sensitive pump, 4 is a shuttle valve, 5 is a pressure reducing valve, 6 is a switch valve, 7 is the first throttling damper, 8 is a one-way valve, 9 is a valve link, 10 is a pressure cut-off valve, 11 is a pilot control valve group, 111 is the second throttling damper, 112 is a pilot control valve, 113 is the third throttling damper, 12 is a hydraulic lock, 13 is a pilot pump, 14 is a second reversing valve, 15 is a pressure compensator, and 16 is a boom cylinder. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The core of the present invention is to provide a control circuit for a hydraulic quick-change device for an excavator to prevent the bucket or other accessories from falling without the need for the main pump and engine of the excavator to be continuously loaded, while ensuring that the hydraulic quick-change device can be opened smoothly when replacing the bucket or other accessories.

[0034] Please refer to Figure 1-Figure 3 , Figure 1 A control principle diagram of a control circuit of a hydraulic quick-change device for an excavator provided in a first specific embodiment of the present invention; Figure 2 A control principle diagram of a control circuit of a hydraulic quick-change device for an excavator provided in a second specific embodiment of the present invention; Figure 3 This is a control principle diagram of a control circuit of a hydraulic quick-change device for an excavator provided in a third specific embodiment of the present invention.

[0035] The present invention provides a control circuit of a hydraulic quick-change device for an excavator, comprising a quick-change oil cylinder 1, a first reversing valve 2, a load-sensitive pump 3, a first hydraulic source and a shuttle valve 4. Specifically, the quick-change oil cylinder 1 comprises a rod chamber and a rodless chamber, the first reversing valve 2 is used to switch the direction of the oil circuit so that the rod chamber and the rodless chamber switch the oil inlet, the first reversing valve 2 is connected to the rod chamber through the rod chamber oil circuit, and is connected to the rodless chamber through the rodless chamber oil circuit; the load-sensitive pump 3 is used to provide a hydraulic source for the boom action of the excavator; the first hydraulic source has hydraulic oil with a stable pressure; the two oil inlets of the shuttle valve 4 are respectively connected to the oil outlet of the load-sensitive pump 3 and the first hydraulic source, and the oil outlet of the shuttle valve 4 and the oil inlet of the first reversing valve 2 are connected through the first oil inlet circuit.

[0036] That is, the present invention selects the higher pressure between the oil outlet of the load sensing pump 3 and the first hydraulic source through the shuttle valve 4, so as to supply oil to the quick-change cylinder 1 using the higher pressure between the oil outlet of the load sensing pump 3 and the first hydraulic source.

[0037] It is understandable that when the excavator is started (at this time, the excavator boom has not yet worked and has not made any movement), the load-sensing pump 3 is in a waiting state, and the pressure at the oil outlet of the load-sensing pump 3 is relatively low. At this time, the pressure at the oil outlet of the load-sensing pump 3 is insufficient to provide reliable pressure for the quick-change cylinder 1, that is, the rodless chamber of the quick-change cylinder 1 cannot enter the high-pressure oil source and maintain pressure, which easily causes the piston rod of the quick-change cylinder 1 to retract, causing the bucket or other accessories to fall. Therefore, the present invention introduces a first hydraulic source to assist in providing a high-pressure oil source to the quick-change cylinder 1. When the excavator is started, the pressure at the oil outlet of the load-sensing pump 3 is relatively low. At this time, the pressure of the first hydraulic source is higher than the pressure at the oil outlet of the high-pressure load-sensing pump 3. Therefore, the first hydraulic source provides hydraulic pressure for the rodless chamber of the quick-change cylinder 1 to ensure that the quick-change cylinder 1 can be locked to prevent the bucket or other accessories from falling.

[0038] When the boom of the excavator moves, the load-sensing pump 3 works, and its oil outlet has a pressure higher than that of the first hydraulic source. At this time, under the action of the shuttle valve 4, the load-sensing pump 3 provides hydraulic oil to the quick-change cylinder 1.

[0039] That is to say, the present invention introduces the first hydraulic source and, under the selection of the shuttle valve 4, can ensure that the first oil inlet circuit has an oil source pressure that is at least not lower than that of the first hydraulic source and is output to the quick-change cylinder 1, which is beneficial to maintaining the pressure in the rodless chamber of the quick-change cylinder 1 and at the same time avoiding continuous loading of the load-sensitive pump 3 and the engine (it can be understood that if the first hydraulic source does not exist and only the load-sensitive pump 3 is used to supply oil to the quick-change cylinder 1, even if the boom of the excavator does not move, the load-sensitive pump 3 and the engine need to be loaded).

[0040] Similarly, when it is necessary to replace the bucket or other accessories, the first reversing valve 2 is switched, and under the action of the shuttle valve 4, the first hydraulic source or the load-sensitive pump 3 can supply oil to the rod chamber of the quick-change cylinder 1, ensuring that the first oil inlet circuit has an oil source pressure at least not lower than that of the first hydraulic source output to the quick-change cylinder 1, so that the quick-change cylinder 1 can be unlocked using high pressure to ensure that the bucket or other accessories can be smoothly disengaged.

[0041] It should be noted that the present embodiment does not limit the specific structure of the first reversing valve 2, as long as it can play a reversing role, such as Figure 1 As shown, preferably, the first reversing valve 2 is an electromagnetic two-position four-way reversing valve. It can be understood that the oil inlet of the first reversing valve 2 is connected to the first oil inlet circuit, the two working oil ports of the first reversing valve 2 are respectively connected to the rod chamber oil circuit and the rodless chamber oil circuit, and the oil return port of the first reversing valve 2 is connected to the oil return circuit so that the oil returns to the oil tank.

[0042] The load sensitive pump 3 is a main pump in the excavator for providing a hydraulic source for the boom movement of the excavator. The structure thereof can be referred to in the prior art and will not be described in detail herein. In the present invention, the load sensitive pump 3 also has the function of providing a hydraulic source for the quick-change cylinder 1 .

[0043] In addition, the first hydraulic source is not specifically limited in this embodiment. For example, the first hydraulic source may include a pilot pump 13. When the oil outlet pressure of the load sensing pump 3 is low, the pilot pump 13 provides a hydraulic source for the quick-change cylinder 1. Of course, the first hydraulic source may also be an accumulator or other oil circuit with stable pressure, as long as it has hydraulic oil with stable pressure.

[0044] In addition, when the excavator is working normally, the pressure at the oil outlet of the load sensing pump 3 is relatively high, usually higher than the requirement of the quick-change oil cylinder 1. Therefore, considering safety, based on the above embodiment, the first oil inlet circuit or the rodless chamber oil circuit is provided with a pressure reducing valve 5. That is to say, by providing a pressure reducing valve 5, the high-pressure oil source during the normal operation of the excavator is decompressed to a set pressure and then output to the rodless chamber of the quick-change oil cylinder 1, so that the quick-change oil cylinder 1 is locked. Figure 1 and Figure 3 As shown, the pressure reducing valve 5 is arranged in the first oil inlet; Figure 2 As shown, the pressure reducing valve 5 is arranged in the rodless chamber oil circuit.

[0045] Furthermore, on the basis of the above-mentioned embodiment, a pressure feedback oil circuit is provided between the first reversing valve 2 and the load-sensitive pump 3, and a switch valve 6 is provided in the pressure feedback oil circuit. The switch valve 6 and the first reversing valve 2 are energized and de-energized at the same time, so that when the first reversing valve 2 is actuated and the oil inlet of the quick-change cylinder 1 changes from the rodless chamber to the rod chamber, the switch valve 6 is opened to feed back the pressure in the rod chamber to the load-sensitive pump 3 through the pressure feedback oil circuit.

[0046] That is to say, when oil flows into the rodless chamber of the quick-change cylinder 1, the switch valve 6 is closed to disconnect the pressure feedback oil circuit. At this time, no feedback pressure is needed to ensure that the rodless chamber has continuous pressure and the quick-change cylinder 1 does not loosen; when the first reversing valve 2 is actuated to allow oil to flow into the rod chamber of the quick-change cylinder 1, the switch valve 6 is opened to connect the pressure feedback oil circuit to switch the working state of the first reversing valve 2 or to feed back the pressure in the rod chamber to the load-sensitive pump 3 through the pressure feedback oil circuit, so that the load-sensitive pump 3 adjusts its flow output according to the pressure fed back by the pressure feedback oil circuit.

[0047] It should be noted that the present embodiment does not limit the specific structure of the switch valve 6. Preferably, the switch valve 6 is a two-position two-way valve.

[0048] Further, on the basis of the above embodiment, a first throttle damper 7 is provided between the intersection of the pressure feedback oil circuit and the first oil inlet circuit and the shuttle valve 4. It can be understood that the cross-sectional area of ​​the throttle port of the first throttle damper 7 and the pressure difference between the two ends of the first throttle damper 7 determine the flow rate of the first oil inlet circuit, that is, the load sensing pump 3 can provide accurate flow output according to the pressure feedback of the pressure feedback oil circuit and the size of the first throttle damper 7 to ensure the smoothness of the action of the quick-change oil cylinder 1.

[0049] In addition, in order to prevent the oil from flowing back in the first oil inlet circuit and the pressure feedback oil circuit, on the basis of the above embodiment, the first oil inlet circuit and the pressure feedback oil circuit are respectively provided with a one-way valve 8. It can be understood that the one-way valve 8 provided on the first oil inlet circuit ensures that the oil can only flow from the shuttle valve 4 to the first reversing valve 2, but not in the reverse direction; the one-way valve 8 provided on the pressure feedback oil circuit ensures that the oil can only flow from the first reversing valve 2 to the load sensing pump 3, but not in the reverse direction.

[0050] Further, considering the convenience of installation, as a preferred solution, on the basis of the above embodiment, the shuttle valve 4, the pressure reducing valve 5, the first throttle damper 7, the first reversing valve 2, the switch valve 6 and the check valve 8 are integrated into a valve link 9. That is to say, in this embodiment, the functions of the shuttle valve 4, the pressure reducing valve 5, the first throttle damper 7, the first reversing valve 2, the switch valve 6 and the check valve 8 are integrated into a structural whole, so that the structural whole is a valve link 9, which can realize the functions of the shuttle valve 4, the pressure reducing valve 5, the first throttle damper 7, the first reversing valve 2, the switch valve 6 and the check valve 8 respectively. At the same time, as a structural whole, it can be installed as a whole, which brings many conveniences to the assembly of the control circuit of the hydraulic quick-change device for the excavator.

[0051] In addition, when the piston rod of the quick-change cylinder 1 moves to the bottom of the rodless chamber or gets stuck during the movement, in order to avoid system overflow loss and ensure hydraulic energy saving and high efficiency, on the basis of the above embodiment, the pressure cut-off valve 10 of the load-sensitive pump 3 is provided with an external control port, and the external control port is connected to the pilot control valve group 11. The pilot control valve group 11 includes a hydraulic oil circuit and an oil return circuit arranged in parallel. The hydraulic oil circuit is provided with a second throttling damper 111 and a pilot control valve 112 in series. The oil inlet of the pilot control valve 112 is connected to the second hydraulic source, the second hydraulic source has hydraulic oil with stable pressure, and the oil return port of the pilot control valve 112 is connected to the oil return circuit, and the oil return circuit is provided with a third throttling damper 113.

[0052] That is to say, this embodiment provides remote pilot pressure control for the external control port of the pressure cut-off valve 10 by adding a pilot control valve group 11, and changes the set pressure of the pressure cut-off valve 10 by connecting the pilot control valve 112 of the pilot control valve group 11 to the second hydraulic source. In this way, when the piston rod of the quick-change cylinder 1 shrinks to the bottom of the rodless chamber or when the piston rod gets stuck during movement, the second hydraulic source provides a certain hydraulic pressure to the pressure cut-off valve 10 by controlling the pilot control valve group 11, so that the load-sensitive pump 3 can be placed in a constant-pressure cut-off state, providing only the minimum flow required to maintain the pressure, thereby eliminating hydraulic overflow losses. At the same time, by adjusting the opening of the pilot control valve 112 in the pilot control valve group 11, it can be suitable for quick-change cylinders 1 with different pressure requirements.

[0053] Preferably, based on the above embodiment, the first hydraulic source and the second hydraulic source are the same hydraulic source.

[0054] It should be noted that the present embodiment does not limit the specific structure of the pilot control valve 112. Preferably, based on the above embodiment, the pilot control valve 112 is an electric proportional pressure reducing valve (such as Figure 1 and Figure 2 As shown), electronically controlled two-position three-way switching valve (as shown Figure 3 In addition, in order to maintain the pressure of the rod chamber and the rodless chamber of the quick-change oil cylinder 1, on the basis of the above embodiment, a hydraulic lock 12 is further included for locking the oil circuit of the rod chamber and the rodless chamber respectively, so as to ensure that the pressure in the rodless chamber or the rod chamber is maintained for a longer time.

[0055] It should be noted that the hydraulic lock 12 and the quick-change cylinder 1 can be a separate structure or an integrated structure, that is, the hydraulic lock 12 can be integrated into the quick-change cylinder 1 so that the quick-change cylinder 1 has a self-pressure-maintaining function.

[0056] In addition, those skilled in the art will appreciate that Figure 1-3 As shown, it also includes a second reversing valve 14, a pressure compensator 15 and a boom cylinder 16, that is, hydraulic oil is provided to the boom cylinder 16 through the load-sensitive pump 3 to control the movement of the boom cylinder 16, thereby realizing the movement of the excavator boom, and the second reversing valve 14 is used to switch the oil inlet direction of the boom cylinder 16.

[0057] It should also be noted that, in this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0058] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0059] The control circuit of the hydraulic quick-change device for excavators provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A hydraulic quick-change device control circuit for an excavator, characterized in that: include: A quick-change oil cylinder (1) comprising a rod chamber and a rodless chamber; A first reversing valve (2) is used to switch the oil supply between the rod chamber and the rodless chamber, the first reversing valve (2) being connected to the rod chamber via a rod chamber oil passage and connected to the rodless chamber via a rodless chamber oil passage; A load sensing pump (3) for providing a hydraulic source for the boom movement of the excavator; A first hydraulic source having hydraulic oil at a stable pressure; A shuttle valve (4), two oil inlets of which are respectively connected to the oil outlet of the load-sensing pump (3) and the first hydraulic source, and the oil outlet of the shuttle valve (4) and the oil inlet of the first reversing valve (2) are connected via a first oil inlet path; A pressure feedback oil circuit is provided between the first reversing valve (2) and the load-sensitive pump (3), and a switch valve (6) is provided in the pressure feedback oil circuit. The switch valve (6) and the first reversing valve (2) are energized and de-energized at the same time, so that when the first reversing valve (2) is actuated and the oil inlet of the quick-change oil cylinder (1) changes from the rodless chamber to the rod chamber, the switch valve (6) is opened to feed back the pressure in the rod chamber to the load-sensitive pump (3) through the pressure feedback oil circuit; The pressure cut-off valve (10) of the load-sensing pump (3) is provided with an external control port, the external control port is connected to a pilot control valve group (11), the pilot control valve group (11) comprises a hydraulic oil circuit and an oil return circuit arranged in parallel, the hydraulic oil circuit is provided with a second throttling damper (111) and a pilot control valve (112) connected in series, the oil inlet of the pilot control valve (112) is connected to a second hydraulic source, the second hydraulic source has hydraulic oil with a stable pressure, the oil return port of the pilot control valve (112) is connected to the oil return circuit, and the oil return circuit is provided with a third throttling damper (113); It also includes a hydraulic lock (12) for locking the rod chamber oil circuit and the rodless chamber oil circuit respectively.

2. The hydraulic quick-change device control circuit for an excavator according to claim 1, characterized in that: The first oil inlet circuit or the rodless chamber oil circuit is provided with a pressure reducing valve (5).

3. The hydraulic quick-change device control circuit for an excavator according to claim 1 or 2, characterized in that: A first throttling damper (7) is provided between the intersection of the pressure feedback oil circuit and the first oil inlet circuit and the shuttle valve (4).

4. The hydraulic quick-change device control circuit for an excavator according to claim 3, characterized in that: The first oil inlet circuit and the pressure feedback oil circuit are respectively provided with a one-way valve (8).

5. The hydraulic quick-change device control circuit for an excavator according to claim 4, characterized in that: The shuttle valve (4), the pressure reducing valve (5), the first throttling damper (7), the first reversing valve (2), the switch valve (6) and the one-way valve (8) are integrated into a valve link (9).

6. The hydraulic quick-change device control circuit for an excavator according to claim 1 or 2, characterized in that: The first hydraulic source and the second hydraulic source are the same hydraulic source.

7. The hydraulic quick-change device control circuit for an excavator according to claim 1 or 2, characterized in that: The pilot control valve (112) is an electric proportional pressure reducing valve, an electric-controlled two-position three-way switching valve, or a hydraulic-controlled two-position three-way switching valve.

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