Restraining structure, restraining machine and restraining equipment
By introducing elastic members into the restraining structure, the restraining member moves axially under the driving of the rotating shaft, the problem of collision between the restraining head and the twisting head during the meshing process is solved, and the effect of protecting the restraining member and the torsion bar is achieved.
Patent Information
- Application Number
- CN202421699958.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-07-17
AI Technical Summary
In the prior art, when the restraint head rotates and the twisting head is embedded and meshed, there is a risk of collision between the restraint head and the twisting head, resulting in the problem of the restraint head breaking or the twisting head bent.
A restraint structure is designed, including a rotating shaft, restraint and elastic parts. Through the expansion and contraction of the elastic member, the restraint is moved in the axial direction of the rotation shaft, and the restraint and the torsion rod are avoided from creating excessive impact force during the meshing process.
It effectively avoids excessive impact force generated during the dynamic engagement of the restraint and the torsion rod, protects the restraint and the torsion rod from injury, and prevents impacting the tray during the dynamic engagement of the restraint and the torsion rod.
Smart Images
Figure CN222883581U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery production technology, and in particular to a restraint structure, a restraint machine and a restraint device. Background Art
[0002] During the formation stage of the battery cell, during the first charge and discharge process, side reactions occur in the battery cell, producing gas and releasing heat, causing the battery cell to expand. The gas remaining between the pole pieces causes lithium precipitation and bulging, affecting the performance of the battery cell. In order to keep the shape of the battery cell unchanged during the charge and discharge process, the battery cell needs to be restrained during the charge and discharge process.
[0003] At present, the battery cells are mainly restrained by restraint machines and restraint trays. The restraint head of the restraint machine will gradually approach the twisting head, and the twisting head will be embedded in the restraint head during the rotation process to achieve connection, so that the restraint head drives the twisting head to rotate. However, in the process of the twisting head being embedded in the restraint head, there is a risk of collision between the restraint head and the twisting head, causing the restraint head to bend or the twisting head to break. Utility Model Content
[0004] The present application provides a restraint structure, a restraint machine and a restraint device, which are used to solve the problem in the prior art that when the restraint head rotates and the twisting head is embedded and engaged, there is a risk of collision between the restraint head and the twisting head, resulting in breakage of the restraint head or bending of the twisting head.
[0005] In one aspect, the present application provides a restraint structure, comprising:
[0006] A rotating shaft, capable of rotating about a first axis, wherein the first axis is a central axis of the rotating shaft;
[0007] A restraining member is circumferentially fixed on the rotating shaft and can rotate around the first axis driven by the rotating shaft. The restraining member has a first position and a second position;
[0008] The elastic member is sleeved on the shaft and connected to the restraining member. The elastic member can move the restraining member between a first position and a second position along a preset direction by telescoping. The preset direction is a direction parallel to the axial direction of the rotating shaft.
[0009] In a possible design, a shaft shoulder is provided on the rotating shaft, the restraining member forms a first end surface, one end of the elastic member abuts against the shaft shoulder, and the other end of the elastic member abuts against the first end surface.
[0010] In one possible design, a first through hole is provided on the restraint member, and the first through hole passes through the restraint member along the radial direction of the rotating shaft; a second through hole is provided on the rotating shaft, and the second through hole passes through the rotating shaft along the radial direction of the rotating shaft; the first through hole or the second through hole is a strip hole, and the length direction of the strip hole is parallel to the axial direction of the rotating shaft, and connecting pins are passed through the first through hole and the second through hole.
[0011] In a possible design, the restraint member is formed with a second end surface, the second end surface is arranged opposite to the first end surface, a convex portion is formed on the second end surface, and the convex portion extends along the axial direction of the rotating shaft.
[0012] In a possible design, the protrusions are arranged along a ring array at the edge of the second end surface, and a U-shaped groove is formed between two adjacent protrusions.
[0013] In a possible design, a fixed sleeve is further included, and the rotating shaft is rotatably connected to the inner wall of the fixed sleeve.
[0014] On the other hand, the present application also provides a restraint machine, including a support seat, a movable seat and the restraint structure as described above, wherein the restraint structure is arranged on the movable seat, a first driving member is arranged on the support seat, and the first driving member is used to drive the movable seat to move axially along the rotating shaft, and a second driving member is arranged on the movable seat, and the second driving member is used to drive the rotating shaft to rotate around the first axis.
[0015] In a possible design, a third driving member and a push rod are further provided on the support seat, one end of the push rod is connected to the third driving member, and the third driving member is used to drive the push rod to move axially along the rotating shaft.
[0016] On the other hand, the present application also provides a restraint device, including the restraint machine and restraint tray as described above, the restraint tray is provided with an end plate, a push plate and a screw, the end plate is provided with a threaded hole, the screw is passed through the threaded hole, and a torsion bar is provided at the end of the screw away from the push plate, and the torsion bar is perpendicular to the screw.
[0017] In a possible design, a through hole corresponding to the push rod is formed on the end plate.
[0018] The beneficial effects of this application are as follows:
[0019] The restraint structure of the present application is provided with an elastic member so that the elastic member is connected to the restraint member. The elastic member can move the restraint member along the axial direction of the rotating shaft through its own expansion and contraction, so that the restraint member can move a certain distance along the axial direction of the rotating shaft while rotating with the rotating shaft. When the torsion bar is embedded in the rotating restraint member, when the torsion bar is just embedded in the groove of the restraint member, it means that the embedding fit is good, and the elastic member is always in the first position during this process; when the torsion bar touches the restraint member, the elastic member further contracts, and the restraint member retreats from the first position (the restraint member retreats to the second position at most), thereby avoiding excessive impact force during the dynamic embedding and engagement process of the restraint member and the torsion bar, thereby protecting the restraint member and the torsion bar from damage, and avoiding the restraint member and the torsion bar from hitting the tray during the dynamic engagement process.
[0020] The restraint machine provided in the present application includes the restraint structure in the present application, and thus also includes all the above-mentioned advantages of the restraint structure.
[0021] The restraint device provided in the present application includes the restraint machine in the present application, and thus also includes all the above-mentioned advantages of the restraint machine. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0023] Figure 1 A schematic diagram of a structure of a restraint structure provided in one embodiment of the present application;
[0024] Figure 2 A structural schematic diagram of a restraint device provided in one embodiment of the present application;
[0025] Figure 3 Another structural schematic diagram of a restraint device provided by an embodiment of the present application;
[0026] Figure 4 Another structural schematic diagram of a restraint device provided for an embodiment of the present application.
[0027] Reference numerals:
[0028] 100, rotating shaft; 110, shoulder; 120, second through hole; 200, restraint member; 210, first end face; 220, second end face; 230, first through hole; 240, convex portion; 250, U-shaped slot; 260, connecting pin; 300, elastic member; 400, fixed sleeve; 500, support seat; 600, movable seat; 710, first driving member; 720, second driving member; 730, third driving member; 800, push rod; 900, restraint tray; 910, end plate; 920, push plate; 930, screw. DETAILED DESCRIPTION
[0029] The technical solution of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0030] Combine the following Figure 1-Figure 4, describing the restraint structure provided in the embodiment of the present application, the restraint structure includes a rotating shaft 100, a restraint member 200 and an elastic member 300, the rotating shaft 100 can rotate around a first axis, and the first axis is the central axis of the rotating shaft 100; the restraint member 200 is circumferentially fixed on the rotating shaft 100, and the restraint member 200 can rotate around the first axis driven by the rotating shaft 100, and the restraint member 200 has a first position and a second position; the elastic member 300 is sleeved on the shaft, and the elastic member 300 is connected to the restraint member 200. The elastic member 300 can move the restraint member 200 between the first position and the second position along a preset direction by telescoping, and the preset direction is parallel to the axial direction of the rotating shaft 100. In some specific embodiments, the restraint 200 and the rotating shaft 100 are respectively provided with key slots, which are strip slots, and the length direction of the strip slots is parallel to the axial direction of the rotating shaft 100. The restraint 200 and the rotating shaft 100 are connected by a key, and the length of the key is less than the length of the key slot, that is, the key can slide in the key slot along its length direction, so that the restraint 200 and the rotating shaft 100 can have an axial relative displacement, so that the restraint 200 can also have an axial displacement while the restraint 200 rotates with the rotating shaft 100. The first position refers to the position of the restraint 200 corresponding to the state where the elastic member 300 is compressed to the minimum; the second position refers to the position of the restraint 200 corresponding to the state where the elastic member 300 is compressed to the maximum.
[0031] By utilizing the technical solution of the above embodiment, an elastic member 300 is provided to connect the elastic member 300 with the restraint member 200. The elastic member 300 can move the restraint member 200 along the axial direction of the rotating shaft 100 through its own expansion and contraction, thereby achieving that the restraint member 200 can move a certain distance along the axial direction of the rotating shaft 100 while rotating with the rotating shaft 100.
[0032] Specifically, during the process of the torsion bar being embedded in the rotating restraint 200:
[0033] When the torsion bar is just embedded in the groove of the restraint piece 200, it indicates that the embedding fit is good, and during this process the elastic piece 300 is always in the first position; when the torsion bar touches the restraint piece 200, the elastic piece 300 further contracts, and the restraint piece 200 retreats from the first position to the second position, thereby avoiding excessive impact force during the dynamic embedding engagement between the restraint piece 200 and the torsion bar, thereby protecting the restraint piece 200 and the torsion bar from damage, and avoiding the restraint piece 200 from hitting the tray during the dynamic engagement between the torsion bar and the restraint piece 200.
[0034] Reference Figure 1As shown, in some embodiments of the present application, the shaft 100 is provided with a shoulder 110, the restraining member 200 is formed with a first end face 210, one end of the elastic member 300 abuts against the shoulder 110, and the other end of the elastic member 300 abuts against the first end face 210. In some specific embodiments, the first end face 210 is provided with an axial hole, the end of the shaft 100 is disposed in the axial hole, and the outer wall of the shaft 100 is slidably matched with the inner wall of the axial hole, so that the shaft 100 and the restraining member 200 are allowed to have axial relative movement. In some specific embodiments, the elastic member 300 is a spring, which is sleeved on the rotating shaft 100, with the left end of the spring abutting against the shaft shoulder 110, and the right end of the spring abutting against the first end face 210. In this way, in the absence of external force, due to the compression force of the spring on the restraint member 200, the restraint member 200 will be at the far right, i.e., the first position; when subjected to external force (the restraint member 200 touches the torsion bar), the spring will further contract, and the restraint member 200 will move to the left, thereby avoiding a large collision force with the torsion bar.
[0035] Reference Figure 1 As shown, in some embodiments of the present application, the restraining member 200 is provided with a first through hole 230, and the first through hole 230 penetrates the restraining member 200 in the radial direction of the rotating shaft 100; the rotating shaft 100 is provided with a second through hole 120, and the second through hole 120 penetrates the rotating shaft 100 in the radial direction of the rotating shaft 100; the first through hole 230 or the second through hole 120 is a bar-shaped hole, and the length direction of the bar-shaped hole is parallel to the axial direction of the rotating shaft 100, and a connecting pin 260 is penetrated through the first through hole 230 and the second through hole 120. In some embodiments, the first through hole 230 is a circular hole, and the second through hole 120 is a bar-shaped hole, and the connecting pin 260 penetrates through the first through hole 230 and the second through hole 120. Thus, when there is no external force, under the action of the spring, the connecting pin 260 abuts against the right side of the strip hole, that is, the restraint 200 is in the first position; similarly, when subjected to external force (the restraint 200 touches the torsion bar), the spring further contracts, the restraint 200 moves to the left, and the connecting pin 260 abuts against the left side of the strip hole, that is, the restraint 200 is in the second position. In other embodiments, the first through hole 230 is a strip hole, the second through hole 120 is a circular hole, and the connecting pin 260 passes through the first through hole 230 and the second through hole 120. In this way, when there is no external force, due to the action of the spring, the connecting pin 260 abuts against the left side of the strip hole, and the restraint 200 is in the first position; similarly, when subjected to external force (the restraint 200 touches the torsion bar), the spring further contracts, and the restraint 200 will move to the left, causing the connecting pin 260 to abut against the right side of the strip hole, that is, the restraint 200 is in the second position.
[0036] By utilizing the technical solution of the above embodiment, by setting the first through hole 230, the second through hole 120 and the connecting pin 260, one of the first through hole 230 and the second through hole 120 is designed as a strip hole, so that the connecting pin 260 passes through the first through hole 230 and the second through hole 120, which is beneficial to increase the circumferential connection stability between the restraint 200 and the rotating shaft 100, and at the same time allows axial relative displacement between the restraint 200 and the rotating shaft 100.
[0037] Reference Figure 1 As shown, in some embodiments of the present application, the restraint 200 is formed with a second end surface 220, the second end surface 220 is arranged opposite to the first end surface 210, and a convex portion 240 is formed on the second end surface 220, and the convex portion 240 extends along the axial direction of the rotating shaft 100. By providing the convex portion 240 on the second end surface 220, during the rotation process of the restraint 200, the thrust of the convex portion 240 on the torsion bar is utilized, so that the torsion bar can drive the screw 930 to rotate.
[0038] Reference Figure 1 As shown, in some embodiments of the present application, the protrusions 240 are arranged along a circular array at the edge of the second end surface 220, and a U-shaped slot 250 is formed between two adjacent protrusions 240. By arranging the protrusions 240 in a circular array at the edge of the second end surface 220, the number of U-shaped slots 250 can be increased, and accordingly, during the rotation of the restraint 200, the probability of the torsion bar entering the U-shaped slot 250 will increase, thereby increasing the embedding fit between the torsion bar and the restraint 200 during the dynamic embedding process.
[0039] Reference Figure 1 As shown, in some embodiments of the present application, the restraint structure further includes a fixed sleeve 400, and the rotating shaft 100 is rotatably connected to the inner wall of the fixed sleeve 400. Specifically, the rotating shaft 100 and the inner wall of the fixed sleeve 400 can be rotatably connected via a bearing, so that the fixed sleeve 400 can protect the internal rotating shaft 100 and the spring, and it is also convenient to install the restraint structure as a whole on the moving seat 600.
[0040] See also Figure 2 , Figure 4As shown, the embodiment of the present application also provides a restraint machine, which includes a support seat 500, a moving seat 600 and the restraint structure in the above embodiment, the restraint structure is arranged on the moving seat 600, the support seat 500 is provided with a first driving member 710, the first driving member 710 is used to drive the moving seat 600 to move along the axial direction of the rotating shaft 100, and the moving seat 600 is provided with a second driving member 720, the second driving member 720 is used to drive the rotating shaft 100 to rotate around the first axis. In some specific embodiments, the first driving member 710 is a linear driver, such as a servo electric cylinder, an electric push rod, a hydraulic cylinder or a cylinder, etc. The first driver can drive the moving seat 600 to move along the axial direction of the rotating shaft 100, thereby driving the restraint structure on the moving seat 600 to move along the axial direction of the rotating shaft 100. The second driving member 720 is a rotary driver, such as a servo motor or a stepping motor, and the second driving member 720 can drive the rotating shaft 100 to rotate around the first axis, thereby driving the restraint member 200 to rotate.
[0041] See also Figure 2 , Figure 4 As shown, in some embodiments, a third driving member 730 and a push rod 800 are further provided on the support seat 500, one end of the push rod 800 is connected to the third driving member 730, and the third driving member 730 is used to drive the push rod 800 to move axially along the rotating shaft 100. Specifically, the third driving member 730 is a linear driver, such as a servo electric cylinder, an electric push rod, a hydraulic cylinder or a cylinder, etc., and the third driving member 730 can drive the push rod 800 to move axially along the rotating shaft 100. In some embodiments, the number of the push rods 800 is at least one, for example, two, three, four, etc., preferably an even number, and symmetrically arranged, so that the thrust on the push plate 920 can be balanced.
[0042] See also Figure 2 , Figure 3 As shown, the embodiment of the present application also provides a restraint device, which includes the restraint machine and the restraint tray 900 as described above. The restraint tray 900 is provided with an end plate 910, a push plate 920 and a screw 930. The end plate 910 is arranged in parallel with the push plate 920. The end plate 910 is fixedly installed on the restraint tray 900. The lower end of the push plate 920 is slidably installed on the slide rail of the restraint tray 900. The slide rail is arranged along the length direction of the restraint tray 900, so that the push plate 920 can move along the length direction of the restraint tray 900. A threaded hole is arranged on the end plate 910, and the screw 930 is inserted into the threaded hole. A torsion bar is arranged at one end of the screw 930 away from the push plate 920. The torsion bar is welded or threadedly connected to the screw 930, and the torsion bar is perpendicular to the screw 930. The screw 930 can be rotated by turning the torsion bar. Rotating the screw 930 can gradually make the end of the screw 930 press against the push plate 920, so that the push plate 920 can make the pole piece fit tightly to avoid deformation of the battery cell during charging.
[0043] In some embodiments, a through hole corresponding to the push rod 800 is formed on the end plate 910 , and the push rod 800 can pass through the through hole, thereby pressing against the push plate 920 before the screw rod 930 presses against the push plate 920 .
[0044] The working process of the restraint device in the embodiment of the present application is as follows:
[0045] The third driving member 730 drives the push rod 800 to push the push plate 920 to move rightward, so that the push plate 920 presses the battery cell tightly;
[0046] The first driving member 710 drives the moving seat 600 to move rightward, and the restraining member 200 on the moving seat 600 moves rightward synchronously. At the same time, the second driving member 720 drives the rotating shaft 100 to rotate, and the rotating shaft 100 drives the restraining member 200 to rotate synchronously.
[0047] When the restraining member 200 moves to the meshing position (the restraining member 200 is about to contact the torsion bar), the rotation speed of the first driving member 710 is adjusted so that the rightward movement speed of the restraining member 200 is kept consistent with the speed at which the torsion bar drives the screw rod 930 to move rightward during the rotation process;
[0048] At the moment when the restraint 200 contacts the torsion bar, if the torsion bar can be completely engaged in the U-shaped slot 250 between the two protrusions 240, it means that the fit is good and the state of the elastic member 300 remains unchanged; if the protrusion 240 of the restraint 200 intermittently touches the torsion bar, the elastic member 300 will further contract, causing the restraint 200 to move left and away from the torsion bar, thereby preventing the protrusion 240 from hitting and damaging the torsion bar;
[0049] At the same time, the restraining member 200 continues to rotate until the torsion bar engages with the U-shaped slot 250 between the two protrusions 240 of the restraining member 200, and the elastic member 300 resets and pushes the restraining member 200 to move rightward. During the rotation process, the screw rod 930 is continuously screwed, so that the right end of the screw rod 930 gradually presses against the push plate 920.
[0050] After the screw rod 930 is pressed against the push plate 920, the second driving member 720 is shut down and the restraining member 200 stops rotating; the first driving member 710 drives the movable seat 600 to move leftward so that the restraining member 200 moves leftward and returns to the initial position; the third driving member 730 drives the top rod 800 to move leftward and returns to the initial position.
[0051] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0053] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0054] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0055] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A restraint structure, characterized in that: include: A rotating shaft, capable of rotating about a first axis, wherein the first axis is a central axis of the rotating shaft; A restraining member, circumferentially fixed on the rotating shaft, capable of rotating around the first axis driven by the rotating shaft, the restraining member having a first position and a second position; An elastic member is sleeved on the rotating shaft and connected to the restraining member. The elastic member can move the restraining member between the first position and the second position along a preset direction by telescoping. The preset direction is a direction parallel to the axial direction of the rotating shaft.
2. The restraint structure according to claim 1, characterized in that: The rotating shaft is provided with a shaft shoulder, the restraining member is formed with a first end surface, one end of the elastic member is in contact with the shaft shoulder, and the other end of the elastic member is in contact with the first end surface.
3. The restraint structure according to claim 1 or 2, characterized in that: A first through hole is provided on the restraint piece, and the first through hole passes through the restraint piece along the radial direction of the rotating shaft; a second through hole is provided on the rotating shaft, and the second through hole passes through the rotating shaft along the radial direction of the rotating shaft; the first through hole or the second through hole is a strip hole, and the length direction of the strip hole is parallel to the axial direction of the rotating shaft, and connecting pins are passed through the first through hole and the second through hole.
4. The restraint structure according to claim 2, characterized in that: The restraining member is formed with a second end surface, the second end surface is arranged opposite to the first end surface, a convex portion is formed on the second end surface, and the convex portion extends along the axial direction of the rotating shaft.
5. The restraint structure according to claim 4, characterized in that: The convex parts are arranged along a ring array at the edge of the second end surface, and a U-shaped groove is formed between two adjacent convex parts.
6. The restraint structure according to claim 1, characterized in that: It also includes a fixed sleeve, and the rotating shaft is rotatably connected to the inner wall of the fixed sleeve.
7. A restraint machine, characterized in that: It includes a supporting seat, a moving seat and the restraint structure described in any one of claims 1 to 6, wherein the restraint structure is arranged on the moving seat, a first driving member is arranged on the supporting seat, the first driving member is used to drive the moving seat to move axially along the rotating shaft, and a second driving member is arranged on the moving seat, the second driving member is used to drive the rotating shaft to rotate around the first axis.
8. The restraint device according to claim 7, characterized in that: A third driving member and a push rod are also provided on the support seat. One end of the push rod is connected to the third driving member. The third driving member is used to drive the push rod to move along the axial direction of the rotating shaft.
9. A restraint device, characterized in that: It includes the restraint machine and restraint tray as described in claim 7 or 8, wherein the restraint tray is provided with an end plate, a push plate and a screw rod, the end plate is provided with a threaded hole, the screw rod is passed through the threaded hole, and a torsion bar is provided at one end of the screw rod away from the push plate, and the torsion bar is perpendicular to the screw rod.
10. The restraint device according to claim 9, characterized in that: The end plate is provided with a through hole corresponding to the push rod.