A processing method and processing tool for a cylinder liner water jacket

Abstract

The application provides a processing method and a processing tool for a cylinder jacket water jacket. The processing method comprises the following steps: obtaining a blank of the cylinder jacket water jacket; supporting the inner side wall of the cylinder jacket water jacket by using a supporting bracket and clamping the outer side wall of the cylinder jacket water jacket by using a vertical lathe chuck, wherein the clamping position of the vertical lathe chuck corresponds to the supporting position of the supporting bracket; rough turning and semi-precision turning the inner hole of the cylinder jacket water jacket; removing the supporting bracket and the vertical lathe chuck; pressing the ear part protruding from the outer side wall in the axial direction by using a pressing plate; precision turning the inner hole for at least twice, so that the inner hole reaches the design size, the cutting depth gradually decreases during each precision turning, and the pressing plate is loosened to release the stress and then the ear part is pressed again between the two precision turnings. The processing method for the cylinder jacket water jacket can eliminate the stress relieving annealing process between the rough turning and the precision turning, thereby improving the processing efficiency of the cylinder jacket water jacket.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine part machining, and particularly relates to a machining method of a cylinder liner water jacket and a machining tool for the cylinder liner water jacket. BACKGROUND

[0002] The cylinder liner water jacket is an engine part which is sleeved with the cylinder liner of a marine low-speed diesel engine to form a cooling water cavity. The cooling water cavity is used to take away the heat generated by the piston when moving in the cylinder liner of the diesel engine through water circulation, so that the temperature of the cylinder liner of the diesel engine is kept within an allowable working range, and the cylinder liner of the diesel engine is prevented from being damaged due to overheating.

[0003] Since the cylinder liner water jacket needs to be sleeved with the outer periphery of the cylinder liner of the diesel engine and form a cooling water cavity with sufficient volume, the cylinder liner water jacket generally has the characteristics of large diameter and thin wall. In the related art, the inner hole diameter of the cylinder liner water jacket used in combination with the marine low-speed diesel engine can reach 600 mm, and the thickness size of most thin-walled parts is only 12 mm, which belongs to a typical large-size thin-walled part. In addition to clamping deformation, residual stress during cutting is also easy to cause deformation of the cylinder liner water jacket. At the same time, due to the water-tightness requirement of the cooling water cavity, the inner hole of the cylinder liner water jacket, especially the side wall of the inner hole which cooperates with the cylinder liner of the diesel engine, requires high machining precision. The above factors result in high processing difficulty of the cylinder liner water jacket.

[0004] In the related art, the commonly used machining process is to first perform rough machining and semi-finishing machining, then deform the cylinder liner water jacket under stress through stress relief annealing or other aging treatment processes to release the stress accumulated due to cutting, and finally perform finishing machining to make the cylinder liner water jacket reach the required size precision.

[0005] However, transporting the cylinder liner water jacket to the annealing furnace and stress relief annealing in the annealing furnace both need to consume a certain amount of working hours, thereby resulting in low processing efficiency of the cylinder liner water jacket. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a machining method of a cylinder liner water jacket and a machining tool for the cylinder liner water jacket, which can improve the processing efficiency of the cylinder liner water jacket.

[0007] The machining method of the cylinder liner water jacket provided by the present application comprises the following steps:

[0008] Obtaining a blank of the cylinder liner water jacket;

[0009] Supporting the inner side wall of the cylinder liner water jacket by using a support bracket and clamping the outer side wall of the cylinder liner water jacket by using a vertical lathe chuck, the clamping position of the vertical lathe chuck and the supporting position of the support bracket correspond one by one;

[0010] rough turning and semi-finish turning the inner hole of the cylinder liner water jacket;

[0011] removing the support bracket and the vertical lathe chuck;

[0012] using a pressing plate to press the ear protruding from the outer wall in the axial direction;

[0013] finishing turning the inner hole at least twice to reach the design size of the inner hole, the cutting depth gradually decreasing each time, and the ear being released from the pressing plate and then being pressed again between the two finishing turns.

[0014] The processing method of the cylinder liner water jacket provided by the present application has at least the following technical effects: on the one hand, the support bracket is used in combination with the vertical lathe chuck for clamping during rough turning and semi-finish turning, which can reduce clamping deformation and improve the processing accuracy during rough turning and semi-finish turning; on the other hand, the cutting depth is reduced during finish turning, and the ear is clamped using a pressing plate, which can avoid the inner hole of the cylinder liner water jacket from being deformed in the radial direction due to clamping, and the finish turning is performed at least twice, thereby reducing the cutting amount of each finish turning and reducing the stress generated, and the stress is released by releasing the clamping between the two finish turnings, so that the cylinder liner water jacket can be processed to the target precision, and the processing method of the cylinder liner water jacket can eliminate the stress relief annealing process between rough turning and finish turning, thereby improving the processing efficiency of the cylinder liner water jacket.

[0015] According to some embodiments of the present application, the pressing force of the pressing plate gradually decreases each time.

[0016] According to some embodiments of the present application, the processing method of the cylinder liner water jacket performs two finish turnings, the cutting depth of the first finish turning is less than or equal to 0.2 mm, and the inner hole has a single side allowance of 0.15 mm.

[0017] According to some embodiments of the present application, the cutting depth of the rough turning is less than or equal to 1 mm, and the single side allowance is 1.5 mm; the cutting depth of the semi-finish turning is less than or equal to 0.4 mm, and the single side allowance is 0.5 mm.

[0018] According to some embodiments of the present application, between the semi-finish turning of the inner hole and the finish turning of the inner hole, further comprising processing holes located on the side surface and the end surface of the cylinder liner water jacket.

[0019] According to some embodiments of the present application, the blank of the cylinder liner water jacket is obtained by casting the cylinder liner water jacket and annealing the cast cylinder liner water jacket.

[0020] According to some embodiments of the present application, after the inner hole reaches the design size, further comprising performing a water tightness test on the processed cylinder liner water jacket.

[0021] The cylinder liner water jacket processing tool according to the application is used for implementing the processing method of the cylinder liner water jacket according to the application, and therefore has the beneficial effects provided by the processing method of the cylinder liner water jacket, which will not be described here again.

[0022] The cylinder liner water jacket processing tool according to the application is used for implementing the processing method of the cylinder liner water jacket according to the application, and therefore has the beneficial effects provided by the processing method of the cylinder liner water jacket, which will not be described here again.

[0023] According to some embodiments of the application, the support bracket comprises a support base, first connecting rods and a top head, one end of each of the first connecting rods is mounted on the support base, the first connecting rods extend outwardly in the radial direction from the support base, a plurality of the first connecting rods are arranged at intervals in the circumferential direction, and the top head is mounted on the other end of each of the first connecting rods and is used for abutting against the inner side wall, and the top head comprises a circular arc surface used for contacting the inner side wall.

[0024] According to some embodiments of the application, the cylinder liner water jacket processing tool comprises a pressure testing bracket, the pressure testing bracket is used for being mounted in the inner hole, the pressure testing bracket comprises partitions and second connecting rods, a plurality of the partitions are arranged at intervals in the axial direction, the partitions are used for separating the inner hole and forming a pressurized chamber, and the second connecting rods are connected between two of the partitions. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the application will become apparent and be readily appreciated from the description of the embodiments, taken in conjunction with the following drawings in which:

[0026] Figure 1 is a flowchart of the processing method of the cylinder liner water jacket according to an embodiment of the application;

[0027] Figure 2 is a clamping schematic diagram of the processing method of the cylinder liner water jacket according to an embodiment of the application when rough turning and semi-finish turning;

[0028] Figure 3 is a clamping schematic diagram of the processing method of the cylinder liner water jacket according to an embodiment of the application when finish turning;

[0029] Figure 4 is an assembly schematic diagram of the processing method of the cylinder liner water jacket according to an embodiment of the application when water tightness testing;

[0030] Figure 5 is a structural schematic diagram of a support bracket of the cylinder liner water jacket processing tool according to an embodiment of the application;

[0031] Figure 6 is a structural schematic diagram of a pressure testing bracket of the cylinder liner water jacket processing tool according to an embodiment of the application.

[0032] REFERENCE NUMERALS:

[0033] supporting bracket 110, support 111, first connecting rod 112, top head 113, vertical lathe chuck 120, pressing plate 130, pressure test support 140, partition plate 141, second connecting rod 142, pre-positioning rod 143, cover plate 150,

[0034] cylinder liner water jacket 900. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only, for the purpose of explanation, and are not to be understood as a limitation of the present application.

[0036] In the description of the present application, it needs to be understood that the orientation description, such as "center", "lengthwise", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, are indicative of the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0037] In the description of the present application, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, more than, and the like are understood as not including the number, above, below, and the like are understood as including the number. If the first, second, and the like are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0038] In the description of the present application, unless otherwise explicitly limited, the words such as setting, mounting, connecting, and the like should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0039] The cylinder liner water jacket 900 requires high machining precision, and the tolerance range of the inner hole size is usually within 0.2 mm. The machining precision and the deformation caused by residual stress will affect the size, so the deformation amount of the inner hole during machining should be controlled to be not more than 0.1 mm.

[0040] The cylinder liner water jacket 900 is generally processed in stages through rough turning, semi-finishing turning and finishing turning. The cutting depth of the turning tool is large during rough turning and semi-finishing turning, and the cutting force generated is also large, and accordingly, a large residual stress is accumulated. In the related art, the residual stress accumulated during the previous processing is released through stress relief annealing or other aging treatment processes before finishing turning, and then the inner hole is processed to the required position through finishing turning. The finishing turning has high processing accuracy and less accumulated residual stress, and thus the required tolerance range can be achieved.

[0041] However, the stress relief annealing takes a long time, and the other aging treatment also generally needs a long time, so that the processing efficiency of the cylinder liner water jacket 900 is not high.

[0042] With reference to Figure 1 , Figure 2 and Figure 3 , the processing method of the cylinder liner water jacket provided by the present application comprises the following steps:

[0043] obtaining a blank of the cylinder liner water jacket 900;

[0044] supporting the inner side wall of the cylinder liner water jacket 900 using the support bracket 110, and clamping the outer side wall of the cylinder liner water jacket 900 using the vertical lathe chuck 120, the clamping position of the vertical lathe chuck 120 corresponding to the supporting position of the support bracket 110 one by one;

[0045] rough turning and semi-finishing turning the inner hole of the cylinder liner water jacket 900;

[0046] removing the support bracket 110 and the vertical lathe chuck 120;

[0047] pressing the ear portion protruding from the outer side wall in the axial direction using the pressing plate 130;

[0048] finishing turning the inner hole at least twice to make the inner hole reach the design size, the cutting depth gradually decreasing during each finishing turning, and the pressing plate 130 being released to release the stress before the second finishing turning, and then the ear portion is pressed again.

[0049] It can be understood that the double-dotted line in the figure is the cylinder liner water jacket 900 in the present application.

[0050] The processing method of the cylinder liner water jacket provided by the present application has the following characteristics.

[0051] Firstly, the support bracket 110 is used to support from the inside, and the supporting force of the support bracket 110 is balanced with the clamping force of the jaws of the vertical lathe chuck 120, so as to reduce the stress deformation of the cylinder liner water jacket 900 during clamping, and improve the processing accuracy during rough turning and semi-finishing turning.

[0052] Next, since the wall thickness of the cylinder liner water jacket 900 is further reduced after rough turning and semi-finish turning, the rigidity is also correspondingly weakened, so the support bracket 110 and the vertical lathe chuck 120 are replaced by the pressing plate 130 for clamping. The pressing plate 130 exerts force from the axial direction to press the cylinder liner water jacket 900, which can reduce the deformation of the inner hole of the cylinder liner water jacket 900 in the axial direction due to clamping, and improve the machining accuracy. Finish turning is performed at least twice, and the cutting depth gradually decreases during each finish turning, thereby reducing the cutting amount during each finish turning and reducing the cutting force. The size of the cutting force can be matched with the clamping method of axial compression, and the reduction of the cutting force can also reduce the internal stress generated. The stress generated during the previous finish turning is released by unclamping and re-clamping between the two finish turnings.

[0053] The above means work together to enable the cylinder liner water jacket machining method to machine the cylinder liner water jacket 900 to the target size tolerance. The cylinder liner water jacket machining method does not need to perform stress relief annealing treatment, can shorten the processing time, improve the processing efficiency, and enable the cylinder liner water jacket 900 to be put into use as soon as possible.

[0054] Considering that the cutting depth gradually decreases during each finish turning, the cutting force during each finish turning also gradually decreases, so the pressing force of the pressing plate 130 during each finish turning can also gradually decrease. Using a smaller pressing force can further reduce the deformation of the inner hole of the cylinder liner water jacket 900 in the axial direction due to clamping.

[0055] In order to balance the processing quality and processing efficiency, for the cylinder liner water jacket 900 with an inner hole size tolerance range of 0.2 mm or less, the cylinder liner water jacket machining method can be set to perform two finish turnings. The cutting depth of the first finish turning should be less than or equal to 0.2 mm, so as to ensure that the cutting force generated does not exceed a reasonable value, and the inner hole of the finish turning has a single-sided allowance of 0.15±0.03 mm, thereby leaving a suitable machining allowance for the next finish turning.

[0056] During rough turning and semi-finish turning, cutting also needs to be constrained. For example, the cutting depth of rough turning can be set to be less than or equal to 1 mm, with a single-sided allowance of 1.5±0.3 mm; the cutting depth of semi-finish turning can be set to be less than or equal to 0.4 mm, with a single-sided allowance of 0.5±0.1 mm.

[0057] In some embodiments, between roughing the inner hole and finishing the inner hole, further comprising, machining the holes on the side surface and the end surface of the cylinder liner water jacket 900. The holes here include various types of holes for connection or communication, such as pin holes, threaded holes, liquid injection holes, observation holes, etc. This step usually needs to be carried out in a machining center, for example, machining the holes on the side surface in a horizontal machining center, and machining the holes on the end surface in a vertical machining center, so the relevant technology can be selected according to the needs, and if the support bracket 110 and the vertical spindle chuck 120 meet the requirements, the original clamping method can also be directly used, which is not limited here. Since the clamping method usually needs to be changed, this process is generally located after the support bracket 110 and the vertical spindle chuck 120 are removed, and before the pressure plate 130 is used to press the ears protruding from the outer wall in the axial direction.

[0058] In some embodiments, the blank of the cylinder liner water jacket 900 is obtained by casting the cylinder liner water jacket 900, and then annealing the cast cylinder liner water jacket 900. Casting can use the casting process commonly used in related technologies, which will not be repeated here.

[0059] In some embodiments, after the inner hole reaches the design size, further comprising, performing a water tightness test on the machined cylinder liner water jacket 900 to ensure that the quality of the cylinder liner water jacket 900 meets the design requirements. Referring to Figure 4 , the water tightness test refers to closing the cylinder liner water jacket 900 through related parts (in Figure 4 , the test pressure bracket 140 and the cover plate 150) to form a plurality of pressurized chambers. The shape of the pressurized chamber is different from that of the cooling water cavity in actual use, but the possible leakage position of the pressurized chamber is consistent with that of the cooling water cavity, so the water tightness of the cooling water cavity can be tested by injecting water into the pressurized chamber.

[0060] The cylinder liner water jacket machining tool provided by the present application is used to implement the machining method of the cylinder liner water jacket provided by the present application, and the cylinder liner water jacket machining tool includes a support bracket 110, a vertical spindle chuck 120, and a pressure plate 130. The support bracket 110 and the vertical spindle chuck 120 are used for clamping during roughing and semi-finishing, and the pressure plate 130 is used for clamping during finishing.

[0061] The cylinder liner water jacket machining tool is used to implement the machining method of the cylinder liner water jacket, so it also has the beneficial effects provided by the machining method of the cylinder liner water jacket, which will not be repeated here.

[0062] Referring to Figure 5In some embodiments, the support bracket 110 comprises a support base 111, a first connecting rod 112 and a top head 113, one end of the first connecting rod 112 is mounted on the support base 111, the first connecting rod 112 extends outwardly from the support base 111 in the radial direction, a plurality of first connecting rods 112 are arranged at intervals in the circumferential direction, and the top head 113 is mounted on the other end of the first connecting rod 112, and the top head 113 is used to abut against the inner side wall.

[0063] The first connecting rod 112 and / or the top head 113 can be installed in a threaded manner, so that the distance of the top head 113 to the support base 111 can be fine-tuned, so that the support force of the support bracket 110 in each direction is more uniform. For example, in Figure 5 , both ends of the first connecting rod 112 are machined with external threads, and the top head 113 uses a nut, so as to realize threaded adjustment.

[0064] In addition, the top head can also comprise a circular arc surface for contacting the inner side wall. The circular arc surface can reduce damage during contact on the one hand, and make the contact position more accurate on the other hand, thereby making the adjustment of the support force more accurate. The circular arc surface can be realized in different ways, for example, the Figure 5 nut of the top head 113 can be replaced by a ball head nut, or the top head 113 can also use some existing ball head standard parts.

[0065] Referring to Figure 6 , the cylinder liner water jacket processing tool also comprises a pressure test bracket 140, the pressure test bracket 140 is used to be mounted in the inner hole, the pressure test bracket 140 comprises a partition plate 141 and a second connecting rod 142, a plurality of partition plates 141 are arranged at intervals in the axial direction, the partition plate 142 is used to separate the inner hole and form a pressurizing chamber, and the second connecting rod 142 is connected between two partition plates 141. The cylinder liner water jacket processing tool also comprises a cover plate 150 used in cooperation with the pressure test bracket 140.

[0066] The partition plate 141 and the second connecting rod 142 can be connected by welding. In order to improve the accuracy of welding, the pressure test bracket 140 can also comprise a pre-positioning rod 143, the pre-positioning rod 143 is connected between the partition plates 141 through threaded holes, pin holes and the like. It should be noted that the threaded holes and the pin holes cannot penetrate the partition plates 141, so as to avoid forming leakage points.

[0067] The surface of the partition plate 141 in contact with the inner side wall is machined in reference to the surface requirements of the engine cylinder liner, and a corresponding sealing groove is made, so as to simulate the condition when the engine cylinder liner and the cylinder liner water jacket 900 are assembled.

[0068] In order to match the cylinder liner water jacket processing tool, the processing method of the cylinder liner water jacket further comprises, before clamping, preparing the cylinder liner water jacket processing tool. The step of preparing the cylinder liner water jacket processing tool further comprises welding the pressure test bracket 140. For details, please refer to Figure 6For example, in the case of the water tightness test with two pressurized chambers, the second connecting rod 142 is divided into the part connected in the pressurized chamber and the part connected between the pressurized chambers according to the pressurized chambers. The second connecting rod 142 in the pressurized chamber is first welded with the corresponding partition plate 141 to form a plurality of sub-brackets; next, each sub-bracket is assembled with the cylinder jacket water jacket 900 and ground in sequence, so as to compensate the welding deformation and make the assembly of the partition plate 141 and the inner wall surface meet the requirements; then the sub-brackets are connected through the predetermined positioning rod 143 and welded through the second connecting rod 142 connected between the pressurized chambers; finally, the assembly and grinding are performed again.

[0069] Through the welding assembly mode of the sub-brackets, the size of the pressure test bracket 140 can meet the requirements.

[0070] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0071] In some alternative embodiments, the functions / operations mentioned in the block diagram can not occur in the order mentioned in the operation diagram. For example, depending on the functions / operations involved, two blocks shown in succession can actually be executed substantially simultaneously or the blocks can sometimes be executed in reverse order. In addition, the embodiments presented and described in the flowcharts of the present application are provided by way of example, with the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operations and logical flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of larger operations are independently executed.

[0072] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method of machining a cylinder liner water jacket, characterized by, The method comprises the following steps: obtaining a blank of a cylinder jacket; supporting the inner side wall of the cylinder jacket by using a support bracket and clamping the outer side wall of the cylinder jacket by using a lathe chuck, the clamping position of the lathe chuck corresponding to the supporting position of the support bracket; rough turning and semi-finish turning the inner hole of the cylinder jacket; removing the support bracket and the lathe chuck; pressing the ear protruding from the outer side wall in the axial direction by using a pressing plate; finish turning the inner hole at least twice to make the inner hole reach the design size, the cutting depth gradually decreasing each time, and the ear being released from the pressing plate and then being pressed again between the two finish turnings; the support bracket comprises a support base, a first connecting rod and a top head, one end of the first connecting rod is installed on the support base, the first connecting rod extends outward from the support base in the radial direction, a plurality of first connecting rods are arranged in the circumferential direction, and the top head is installed on the other end of the first connecting rod, the top head being used for abutting against the inner side wall, and the top head comprising a circular arc surface for contacting the inner side wall.

2. The cylinder liner water jacket processing method according to claim 1, characterized by, The pressing force of the pressing plate gradually decreases each time.

3. The cylinder liner water jacket processing method according to claim 1 or 2, characterized by, The processing method of the cylinder jacket is performed twice, the cutting depth of the first finish turning is less than or equal to 0.2 mm, and the inner hole has a single-sided allowance of 0.15±0.03 mm.

4. The cylinder liner water jacket processing method according to claim 3, characterized by, The cutting depth of the rough turning is less than or equal to 1 mm, and the single-sided allowance is 1.5±0.3 mm; the cutting depth of the semi-finish turning is less than or equal to 0.4 mm, and the single-sided allowance is 0.5±0.1 mm.

5. The method of claim 4, wherein Between the semi-finish turning of the inner hole and the finish turning of the inner hole, the method further comprises processing holes on the side surface and the end surface of the cylinder jacket.

6. The method of claim 1, wherein The blank of the cylinder jacket is obtained by casting the cylinder jacket and annealing the cast cylinder jacket.

7. The method of claim 1, wherein After the inner hole reaches the design size, the method further comprises performing a water tightness test on the processed cylinder jacket.

8. A cylinder liner water jacket processing tool characterized by, The processing tooling for the cylinder jacket is used to implement the processing method of the cylinder jacket according to any one of claims 1 to 7, and comprises a support bracket, a lathe chuck and a pressing plate, the support bracket comprises a support base, a first connecting rod and a top head, one end of the first connecting rod is installed on the support base, the first connecting rod extends outward from the support base in the radial direction, a plurality of first connecting rods are arranged in the circumferential direction, the top head is installed on the other end of the first connecting rod, the top head is used for abutting against the inner side wall, and the top head comprises a circular arc surface for contacting the inner side wall.

9. The cylinder liner jacketing tooling of claim 8, wherein, The processing tooling for the cylinder jacket comprises a pressure testing bracket, the pressure testing bracket is used to be installed in the inner hole, and the pressure testing bracket comprises a partition plate and a second connecting rod, a plurality of partition plates are arranged in the axial direction, the partition plates are used to divide the inner hole and form a pressurizing chamber, and the second connecting rod is connected between two partition plates.

Images