Screw element fixing jig and screw element fixing structure

Abstract

The utility model provides a clamp for fixing a screw element and a structure for fixing the screw element. The purpose of the present invention is to suppress deviation of surface pressure applied between screw elements when a plurality of screw elements are fixed to a screw shaft in accordance with the sense of force of an operator. A screw element fixing jig (100) is provided with: an externally fitted sleeve (112) which is externally fitted to the outer peripheral surface of a fixing nut (24) of a screw element (3) and which comes into contact with the end surface of a tip screw element (3S); a hydraulic nut (113) having a nut body part (113a), a cylinder chamber (113b) formed in the nut body part, and a piston (113c) for pressing the outer sleeve toward the tip screw element side; and an attachment male thread shaft section (111) having, on the outer peripheral surface thereof, a hydraulic nut male thread section (111d) for threaded engagement with the hydraulic nut, the attachment male thread shaft section (111) being attached coaxially to the mixing screw (1) at the tip-side end of the mixing screw (1). An opening (112a) through which a tool for rotating the fixing nut can be inserted is formed in the outer sleeve.

Description

Technical Field

[0001] This utility model relates to a screw element fixing clamp and a screw element fixing structure used in a mixing screw having a screw shaft, a plurality of screw elements, and a fixing component for fastening the plurality of screw elements, wherein the screw elements are fixed by the fixing component. Background Technology

[0002] Previously, a mixing screw was known, which had a screw shaft, a plurality of screw elements that were fitted into the outer circumferential surface of the screw shaft by spline connection and arranged axially with each other, and a fixing component for fastening and fixing the plurality of screw elements.

[0003] In the mixing screw shown in Patent Document 1 below, a circular plate-shaped collar is used as the aforementioned fixing component. The collar clamps and fixes multiple screw elements externally embedded in the screw shaft between itself and a stepped surface formed on the screw shaft. The aforementioned collar is fixed to the front end face of the screw shaft with bolts.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-34376 Utility Model Content

[0007] The problem to be solved by utility models

[0008] Furthermore, in the mixing screw with multiple screw elements shown in Patent Document 1, a certain surface pressure needs to be applied between each screw element to prevent the material to be mixed (e.g., molten resin in the case of applying the mixing screw to an extruder) from intruding into the gaps between the screw elements. However, in the mixing screw of Patent Document 1, the following structure is used: after the operator externally inserts multiple screw elements onto the screw shaft, a collar serving as a fixing component is pushed against the end face of the screw element located closest to the front end of the shaft and screwed in with a bolt, thereby ensuring the surface pressure. Therefore, there is a problem that the surface pressure between the elements may deviate depending on the tightening of the bolt by the operator (the operator's force).

[0009] This invention was made to solve the aforementioned problems, and its purpose is to provide a screw element fixing clamp and a screw element fixing structure that can suppress the deviation of the surface pressure applied between each screw element according to the operator's force perception when fixing multiple screw elements to the screw shaft.

[0010] Methods used to solve problems

[0011] The first embodiment is a clamp for fixing screw elements. In a mixing screw comprising a screw shaft, multiple screw elements, and a fixing component, it is used when the fixing component fixes the multiple screw elements. The screw shaft has a stepped surface formed perpendicular to its axis. The multiple screw elements are fitted into the outer peripheral surface of the screw shaft via splines and are arranged axially adjacent to each other, with their axial positions restricted by the stepped surface. The fixing component clamps and secures the multiple screw elements between itself and the stepped surface. The mixing screw includes: a fixing nut serving as the fixing component, abutting against the end face of the frontmost screw element among the multiple screw elements; and a male threaded portion for the fixing nut, provided on the side of the mixing screw opposite to the stepped surface. The end of the front end is used to thread the aforementioned fixing nut onto its outer peripheral surface; the aforementioned screw element fixing clamp includes: an outer nesting cylinder, which is fitted onto the outer peripheral surface of the aforementioned fixing nut and abuts against the end face of the aforementioned front screw element on the radially outer side of the fixing nut; a hydraulic nut, which has a nut body, a cylinder chamber formed in the nut body, and a piston driven by working oil supplied to the cylinder chamber to push the aforementioned outer nesting cylinder toward the aforementioned front screw element; and a mounting male threaded shaft, which has a male threaded portion for threading the aforementioned hydraulic nut onto its outer peripheral surface and is coaxially mounted with the aforementioned mixing screw at the end of the front end of the aforementioned mixing screw; the aforementioned outer nesting cylinder has an opening formed radially through it, through which a tool for rotating the aforementioned fixing nut about its axis can be inserted.

[0012] According to this structure, it is possible to suppress deviations in the surface pressure applied between the screw elements when fixing multiple screw elements to the screw shaft, based on the operator's force perception. Specifically, according to this structure, working oil is supplied to the cylinder chamber of the hydraulic nut using a hydraulic pump or the like, and the piston of the hydraulic nut pushes the outer nesting cylinder towards the front screw element side. As a result, the multiple screw elements are compressed axially between the stepped surfaces of the outer nesting cylinder and the aforementioned screw shaft. Consequently, a gap is generated between the front screw element and the fixing nut (fixing component). Therefore, by the operator screwing in the fixing nut to fill this gap, it is possible to prevent over-tightening or under-tightening of the fixing nut, thus ensuring uniform and sufficient surface pressure between the screw elements. This prevents deformation of the screw elements and crushing of the threads caused by over-tightening of the fixing nut, and also prevents a decrease in surface pressure between the screw elements caused by under-tightening of the fixing nut. Furthermore, according to this structure, an opening is formed in the outer nesting cylinder for inserting a tool that allows the fixing nut to rotate around its axis, so the aforementioned fixing nut can be easily screwed in even from the outside of the outer nesting cylinder. Additionally, the hydraulic supply to the hydraulic nut and the screwing in of the fixing nut can be performed multiple times. This allows the axial compressive load applied to the multiple screw elements to be increased in stages, so the fixing nut can be screwed in gradually compared to a sudden increase in compressive load. This more reliably prevents the aforementioned problems of under-screwing and over-screwing of the fixing nut.

[0013] The second embodiment, in the first embodiment, preferably further comprises: a hydraulic pump connected to the aforementioned cylinder chamber of the aforementioned hydraulic nut, capable of supplying working oil to the cylinder chamber for driving the aforementioned piston; and a pressure gauge for measuring and displaying the hydraulic pressure of the working oil supplied to the aforementioned cylinder chamber.

[0014] According to this structure, by observing the pressure gauge readings and adjusting the hydraulic pump operation to ensure the hydraulic pressure supplied to the hydraulic nut is at a preset value, the axial compressive load exerted by the hydraulic nut on multiple screw elements can be managed with high precision. Furthermore, it prevents deviations in surface pressure between the screw elements after the fixing nut is tightened.

[0015] In the third embodiment, as in the first embodiment, it is preferred that the opening of the aforementioned outer nested cylinder is formed by an elongated hole that extends in the circumferential direction.

[0016] According to this structure, when screwing in the fixing nut, the tool inserted through the opening can be easily rotated in the circumferential direction. This allows for easy screwing in of the fixing nut. Furthermore, by rotating the tool within a defined angular range from one end of the opening to the other in the circumferential direction, over-screwing of the fixing nut can be prevented.

[0017] In the fourth embodiment, among any one of the embodiments of the first to the third, it is preferred that the aforementioned outer nesting cylinder has a plurality of the aforementioned openings; the plurality of the aforementioned openings are formed by being spaced apart in the circumferential direction of the aforementioned outer nesting cylinder.

[0018] According to this structure, by forming multiple openings spaced apart in the circumferential direction on the outer nesting cylinder, the insertion part of the tool is not limited to one location compared to the case where only one opening is formed, which correspondingly improves the operability of the screwing-in operation of the fixing nut.

[0019] In the fifth option, the preferred embodiment of the second option is that the aforementioned hydraulic pump is a manual pump that manually sprays out the working oil.

[0020] According to this structure, by using a manual pump to form the hydraulic pump, even in situations where a hydraulic pump is not installed in a factory work area, the operator can supply hydraulic pressure to the hydraulic nut using an easily portable manual pump. Therefore, hydraulic pressure can be supplied to the hydraulic nut without the use of large-scale equipment, thus simplifying the operation.

[0021] In the sixth embodiment, among any one of the embodiments of the first to the third, it is preferred that a female threaded hole open to the front end is formed at the axial center of the end portion of the aforementioned mixing screw on the aforementioned front end side; the aforementioned mounting male threaded shaft portion has: a first male threaded shaft portion including an outer peripheral surface on which the aforementioned male threaded portion for hydraulic nuts is formed; and a second male threaded shaft portion connected to the base end side of the first male threaded shaft portion and threadedly engaged with the aforementioned female threaded hole.

[0022] According to this structure, the mounting male threaded shaft portion can be easily installed on the front end side shaft portion of the screw shaft. That is, according to this structure, by threading the second male threaded shaft portion of the mounting male threaded shaft portion into the female threaded hole formed on the front end side shaft portion of the screw shaft (more specifically, the axial center portion of the first male threaded shaft portion of the front end side shaft portion), the mounting male threaded shaft portion can be easily installed on the aforementioned front end side shaft portion of the screw shaft.

[0023] In the seventh embodiment, the sixth embodiment preferably further includes a fastening head, which is rotatably and integrally mounted relative to the aforementioned first male threaded shaft portion. The fastening head has: a connecting plate portion, which is rotatably and integrally connected to the end face of the aforementioned front end side of the aforementioned first male threaded shaft portion; and a protruding engaging portion, which is provided on the surface of the connecting plate portion opposite to the surface connected to the aforementioned first male threaded shaft portion, and is capable of engaging with a tool used to rotate the fastening head about its axis.

[0024] According to this structure, the installation of the male threaded shaft can be performed via a fastening head, thus allowing for easy and secure installation of the male threaded shaft on the front end side of the screw shaft without loosening. Specifically, after the operator rotates the fastening head to the first male threaded shaft of the installation, a rotating tool (such as a wrench) engages with the protruding engaging portion formed on the fastening head, causing the male threaded shaft to rotate around its axis. As a result, the second male threaded shaft of the installation engages with the female threaded hole formed on the front end side of the screw shaft while rotating, facilitating the easy installation of the male threaded shaft.

[0025] In the eighth embodiment, the preferred embodiment is that the aforementioned screw shaft includes: a screw shaft body, which is splinedly connected to the aforementioned screw element; and a front end side shaft portion, which is coaxially connected to the aforementioned screw shaft body and separately at the aforementioned front end side end of the aforementioned screw shaft body, and is thinner than the aforementioned screw shaft body; and the aforementioned male thread portion for fixing nut is provided on the outer peripheral surface of the aforementioned front end side shaft portion.

[0026] According to the eighth embodiment, the screw shaft body does not have a male threaded portion for the fixing nut. Consequently, the axial length of the material used for the screw shaft body can be shortened. Furthermore, as a separate part from the screw shaft body, only a front-end shaft portion that is thinner than the screw shaft body needs to be purchased, avoiding the waste of cost associated with purchasing materials that are thicker than required. Therefore, compared to manufacturing the mixing screw as a component identical to the screw shaft body, the mixing screw can be manufactured more cost-effectively. In other words, when the screw shaft body, which is splined with the aforementioned screw element, has a male threaded portion for the fixing nut, the material used for the screw shaft body must be a shaft-shaped material that extends further towards the front end than the outer peripheral spline portion used for splined engagement with the screw element. Therefore, its axial length increases, and the material cost of the screw shaft body increases accordingly. Furthermore, the portion of the male threaded part for the fixing nut formed on the front end side of the screw shaft needs to be machined to a shape thinner than the portion of the screw shaft body that forms the outer peripheral spline, so that the screw shaft body can pass through the inner peripheral spline of the screw element when the screw element is splined with the screw shaft body. In other words, the portion of the screw shaft body material that extends further towards the front end than the outer peripheral spline portion to form the male threaded part for the fixing nut is larger than the required diameter, resulting in a wasteful increase in material costs. In contrast, according to the aforementioned structure, by integrally constructing the screw shaft body and the male threaded part for the fixing nut, these problems can be avoided.

[0027] The ninth embodiment is a screw element fixing structure, including a screw element fixing clamp of any one of the embodiments of the first to the eighth embodiment, the aforementioned male threaded portion of the aforementioned fixing nut of the mixing screw, and the aforementioned fixing nut.

[0028] Based on this structure, the same effect as schemes 1 to 7 can be obtained.

[0029] Utility Model Effect

[0030] According to this invention, it is possible to suppress the deviation of the surface pressure applied between each screw element when fixing multiple screw elements to the screw shaft, based on the operator's force perception. Attached Figure Description

[0031] Figure 1 This is a schematic diagram showing the usage state of the screw element fixing fixture in the embodiment of this utility model when it is used in the assembly of the mixing screw.

[0032] Figure 2 It is an enlarged cross-sectional view showing the front end of the mixing screw.

[0033] Figure 3 This indicates that a shaft mounting fixture or similar device is installed at the front end of the screw shaft. Figure 1 The diagram is enlarged and shown in part III.

[0034] Figure 4 This indicates the state of hydraulic pressure being supplied to the hydraulic nut. Figure 3 A fairly accurate diagram.

[0035] Figure 5 This refers to the engagement state between the tightening tool and the fixing nut when the tightening tool is used to screw in the fixing nut. Figure 3 The diagram is equivalent to the V-V line cross section. Detailed Implementation

[0036] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0037] Figure 1 This is a schematic diagram showing the usage state of the screw element fixing fixture 100 in the embodiment when it is used in the assembly of the mixing screw 1. Hereinafter, the structure of the mixing screw 1 will be described first, and then the details of the screw element fixing fixture 100 will be described.

[0038] [Mixing Screw]

[0039] In this example, the mixing screw 1 is constructed in a segmented manner, consisting of multiple screw elements 3 assembled on a single screw shaft 2. The application of the mixing screw 1 is not particularly limited, but as an example, it can be used to melt and mix resin materials in an extruder or similar device.

[0040] Figure 2This is an enlarged cross-sectional view of the front end of the mixing screw 1, showing the assembled state of the screw element 3 relative to the mixing screw 1. In the following description, unless otherwise specified, the front end side and the base end side refer to the front end side and the base end side of the mixing screw 1 (screw shaft 2).

[0041] As shown in the figure, the mixing screw 1 has the aforementioned screw shaft 2 and the aforementioned plurality of screw elements 3 (in Figure 2 The components are: a fixing nut 24 for securing the plurality of screw elements 3 to the screw shaft 2, a cover 26 for covering the front end of the screw shaft 2, and a spacer 25. Furthermore, in the following description, when it is necessary to distinguish the screw element 3 closest to the front end from the other screw elements 3, it will be referred to as the front screw element 3S.

[0042] Multiple screw elements 3 are externally embedded on the outer circumferential surface of the screw shaft 2 via spline engagement, and are arranged axially without gaps. On the outer circumferential surface of each screw element 3, a blade portion 3b is formed that projects spirally around its axis. On the inner circumferential surface of each screw element 3, an inner circumferential spline portion 3a is formed, consisting of multiple spline protrusions arranged circumferentially. The inner circumferential spline portion 3a engages with the outer circumferential spline portion 21a formed on the outer circumferential surface of the screw shaft body 21 of the screw shaft 2.

[0043] The screw shaft 2 has a screw shaft body 21 and a base end side shaft portion 22 connected to the base end side of the screw shaft body 21 (only on the base end side). Figure 1 The base end shaft portion 22 is formed with a diameter larger than that of the screw shaft body 21. At the boundary between the screw shaft body 21 and the base end shaft portion 22 in the screw shaft 2, an annular stepped surface 2a perpendicular to the axis of the screw shaft 2 is formed (only on the screw shaft body 21). Figure 1 (This is from the Chinese text.)

[0044] Reference Figure 2 On the outer peripheral surface of the screw shaft body 21, an outer peripheral spline portion 21a is formed that engages with the inner peripheral spline portion 3a of each of the aforementioned screw elements 3. The outer peripheral spline portion 21a is composed of a plurality of spline protrusions arranged circumferentially on the screw shaft body 21. Furthermore, at the front end of the screw shaft body 21, a female threaded hole 21b that opens to the front end side is formed. The female threaded hole 21b is formed coaxially with the screw shaft body 21.

[0045] The front end side shaft portion 23 has a first male threaded shaft portion 23a and a second male threaded shaft portion 23b connected to the base end side of the first male threaded shaft portion 23a.

[0046] On the outer peripheral surface of the first male threaded shaft portion 23a, a fixing nut 24 (described later) is formed (see reference). Figure 3The male threaded portion 23d is used for fixing nuts with threaded engagement. In the axial part of the first male threaded shaft portion 23a, a female threaded hole 23e is formed that opens to the front end side and engages with the mounting male threaded shaft portion 111 described later.

[0047] On the outer peripheral surface of the second male threaded shaft portion 23b, a male threaded portion 23c for the screw shaft body is formed, which is threadedly engaged with the female threaded hole 21b of the aforementioned screw shaft body 21.

[0048] The stepped surface 23f located at the boundary between the first male threaded shaft portion 23a and the second male threaded shaft portion 23b in the front end side shaft portion 23 abuts against the front end surface of the screw shaft body 21.

[0049] The fixing nut 24 clamps and fixes the aforementioned plurality of screw elements 3 together between the stepped surface 2a of the aforementioned screw shaft 2. Specifically, the fixing nut 24 has a nut body portion 24a and a protruding large-diameter portion 24b.

[0050] The nut body 24a is formed into a generally cylindrical shape that threadedly engages with the outer peripheral surface (i.e., the male threaded portion 23d for fixing the nut) of the first male threaded shaft portion 23a of the aforementioned front end side shaft portion 23. At the front end of the nut body 24a, a plurality of through holes 24c extending radially are formed. Viewed axially from the nut body 24a, the plurality of through holes 24c are arranged at equal intervals in the circumferential direction (see below). Figure 5 In this example, the number of through holes 24c is set to twelve, and these twelve through holes 24c are formed at equal intervals of 30° in the circumferential direction. The through holes 24c are formed to allow the insertion of a tightening tool 116 for screwing in the fixing nut 24. By screwing in the fixing nut 24, an axial compressive load is applied to the plurality of screw elements 3 clamped between the fixing nut 24 and the stepped surface 2a of the screw shaft 2.

[0051] Back Figure 2 The aforementioned large-diameter portion 24b is formed as a cylindrical shape that protrudes radially outward from the base end side of the outer peripheral surface of the nut body portion 24a. The fixing nut 24 is threadedly engaged with the aforementioned fixing nut male thread portion 23d in such a way that the end face of the base end side of the large-diameter portion 24b abuts against the front end face of the front end screw element 3S.

[0052] The aforementioned nut body 24a is configured such that, when the aforementioned protruding large-diameter portion 24b abuts against the front end face of the front end screw element 3S, a gap is generated between the base end face of the nut body 24a and the front end face of the screw shaft body 21.

[0053] The aforementioned cover 26 has a cylindrical portion 26a that is externally embedded on the outer peripheral surface of the nut body portion 24a of the fixing nut 24, and a conical portion 26b that covers the front end of the cylindrical portion.

[0054] The spacer 25 is a cylindrical component externally embedded in the outer peripheral surface of the protruding large-diameter portion 24b of the fixing nut 24, and is disposed between the front end face of the front screw element 3S and the base end face of the cover 26. The spacer 25 is formed such that its thickness increases towards the front end, and its front end face constitutes the seat surface of the cover 26.

[0055] After the tightening of the fixing nut 24 is completed, the aforementioned cover 26 and spacer 25 are installed at the front end of the screw shaft 2 (specifically, the front end side shaft 23).

[0056] [Regarding assembly fixtures]

[0057] Furthermore, if the tightening of the fixing nut 24 relies on the operator's force, deviations in surface pressure will occur between the screw elements 3. Therefore, there is a concern that insufficient tightening will create gaps between the screw elements 3, allowing the material to be mixed (the material to be mixed) to intrude into these gaps. Conversely, excessive tightening may cause deformation of the screw elements 3 or crushing of the threads of the fixing nut 24. To avoid this problem, in this embodiment, a screw element fixing clamp 100 is used when fixing the screw elements 3 with the fixing nut 24.

[0058] like Figure 1 As shown, the screw element fixing fixture 100, if roughly divided, consists of a shaft mounting fixture type 110 and a hydraulic supply fixture type 120.

[0059] Figure 3 This indicates that a shaft mounting fixture 110 is installed at the front end of the screw shaft 2. Figure 1 The diagram is enlarged and shown in part III.

[0060] As shown in the figure, the shaft mounting fixture type 110 has a mounting male threaded shaft portion 111, an outer nested cylinder 112, a hydraulic nut 113, and a fastening head 114. However, the fastening head 114 is not necessarily required.

[0061] The mounting male threaded shaft portion 111 is a male threaded shaft portion assembled at the front end side shaft portion 23 of the screw shaft 2. Specifically, the mounting male threaded shaft portion 111 includes: a first male threaded shaft portion 111a; a second male threaded shaft portion 111b, located closer to the base end of the first male threaded shaft portion 111a and assembled at the aforementioned front end side shaft portion 23; and a connecting shaft portion 111c, connecting the first male threaded shaft portion 111a and the second male threaded shaft portion 111b. A male threaded portion 111d for a hydraulic nut is formed on the outer peripheral surface of the first male threaded shaft portion 111a. A male threaded portion 111e for the front end side shaft portion is formed on the outer peripheral surface of the second male threaded shaft portion 111b. The outer peripheral surface of the connecting shaft portion 111c is formed into an arcuate surface whose central portion in its axial direction is recessed radially inward compared to both ends.

[0062] The outer nesting cylinder 112 is composed of a cylindrical component that is externally embedded in the outer peripheral surface of the protruding large-diameter portion 24b of the fixing nut 24. The end face of the base end of the outer nesting cylinder 112 is radially outside the protruding large-diameter portion 24b of the aforementioned fixing nut 24 and abuts against the end face of the front end of the front end screw element 3S.

[0063] At the end of the outer nested cylinder 112 on the front end side, a plurality of radially penetrating openings 112a are formed. The number of openings 112a is, for example, three. (As will be described later.) Figure 5 As shown, the three openings 112a are arranged at equal intervals (every 120°) in the circumferential direction around the axis of the outer nested cylinder 112. Each opening 112a is formed by an elongated hole that is longer in the circumferential direction. Each opening 112a is formed such that the angle θ from one end to the other in the circumferential direction is, for example, 30° when viewed from above.

[0064] The hydraulic nut 113 is a part used to push the outer nested cylinder 112 toward the base end side, and it is threadedly engaged with the hydraulic nut male thread portion 111d of the mounting male threaded shaft portion 111. Specifically, the hydraulic nut 113 has a nut body portion 113a, a cylinder chamber 113b, and a piston 113c. The nut body portion 113a is threadedly engaged with the hydraulic nut male thread portion 111d of the mounting male threaded shaft portion 111. The nut body portion 113a has an annular groove portion that opens toward the base end side and forms the wall surface of the cylinder chamber 113b. The piston 113c has an annular sliding portion 113d that can slide axially with respect to the annular groove portion, and an outer cylinder side of the annular sliding portion 113d. Figure 4The piston 113c is configured such that the push plate portion 113e is connected to the end face of the outer nested cylinder 112. The aforementioned cylinder chamber 113b is formed between the end face of the annular sliding portion 113d of the aforementioned piston 113c and the bottom surface of the annular groove portion. In the aforementioned nut body portion 113a, a hydraulic supply port 113g for supplying working oil to the cylinder chamber 113b and a connecting oil passage 113f connecting the hydraulic supply port 113g to the cylinder chamber 113b are also formed. The hydraulic supply port 113g is connected to the hand pump 121 (described later) via a hydraulic supply hose 122.

[0065] The fastening head 114 is a component used to fasten the mounting male threaded shaft portion 111 to the front end side shaft portion 23 (specifically, the female threaded hole 23e). Specifically, the fastening head 114 has: a circular plate-shaped connecting plate portion 114a, connected to the end face of the first male threaded shaft portion 111a via a pair of connecting pins 115; and a hexagonal head 114b, fixed to the side of the connecting plate portion 114a opposite to the side connected to the aforementioned first male threaded shaft portion 111a. The hexagonal head 114b is coaxially connected relative to the aforementioned connecting plate portion 114a. By attaching the fastening head 114 to the mounting male threaded shaft portion 111, the operator integrates the fastening head 114 with the mounting male threaded shaft portion 111. In this state, by engaging a tool such as a wrench with the hexagonal head 114b, the mounting male threaded shaft portion 111 can be easily rotated around its axis. This simplifies the operation of fastening (installing) the mounting male threaded shaft portion 111 to the female threaded hole 23e of the front end side shaft portion 23.

[0066] Next, the hydraulic supply clamp type 120 will be described. The hydraulic supply clamp type 120 is a clamp type used to supply working oil to the hydraulic nut 113, which is a component of the aforementioned shaft mounting clamp type 110. Specifically, the hydraulic supply clamp type 120 includes a manual pump 121, a hydraulic supply hose 122, and a pressure gauge 123.

[0067] The manual pump 121 has a pump body 121a and a lever 121b. The manual pump 121 is configured such that pressurized working oil is sprayed out from the hydraulic nozzle 121c of the pump body 121a by moving the lever 121b up and down with its base end as a fulcrum.

[0068] The hydraulic supply hose 122 is a hose used to supply working oil ejected from the pump body 121a to the hydraulic nut 113. Specifically, one end of the hydraulic supply hose 122 is connected to the hydraulic outlet 121c of the pump body 121a, and the other end is formed in the hydraulic supply port 113g of the hydraulic nut 113.

[0069] Pressure gauge 123 measures the pressure of the working oil supplied from pump body 121a to hydraulic nut 113 at the current time and displays its measurement on a display (in this case, a dial indicator).

[0070] [Regarding the order of assignments]

[0071] Next, the assembly sequence of the mixing screw 1, which is fixed to the clamp 100 using the aforementioned screw element, will be explained.

[0072] First, the initial operator sequentially installs multiple screw elements 3 (in the screw shaft body 21 of the screw shaft 2) Figure 3 The text only refers to the front-end screw element (3S).

[0073] Then, after the operator has completed the installation of the front screw element 3S, the fixing nut 24 is threaded into the outer peripheral surface (male threaded portion 23d of the fixing nut) of the front side shaft portion 23 of the screw shaft 2.

[0074] Then, the fixing nut 24 is screwed in until the end face of its protruding large diameter portion 24b abuts against the end face of the front end screw element 3S. Then, the operator inserts the outer nesting sleeve 112 onto the outer peripheral surface of the protruding large diameter portion 24b of the fixing nut 24.

[0075] Next, the operator assembles the male threaded shaft portion 111 onto the front end shaft portion 23. Specifically, the second male threaded shaft portion 111b of the male threaded shaft portion 111 is threaded into and tightened into the female threaded hole 23e of the front end shaft portion 23 of the screw shaft 2. At this time, in this example, the tightening head 114 is installed on the end face of the front end side of the male threaded shaft portion 111 via the connecting pin 115, and the wrench is engaged with the hexagonal head 114b of the tightening head 114 to perform the tightening operation. Alternatively, the tightening operation can be performed by directly holding the first male threaded shaft portion 111a of the male threaded shaft portion 111 with a tool without using the tightening head 114, or it can be performed by hand without using a tool.

[0076] Next, the operator installs the hydraulic nut 113 onto the outer peripheral surface of the mounting male threaded shaft portion 111. Specifically, the hydraulic nut 113 is threaded onto the outer peripheral surface of the first male threaded shaft portion 111a (male threaded portion 111d for the hydraulic nut) of the mounting male threaded shaft portion 111. At this time, hydraulic pressure has not yet been supplied to the cylinder chamber 113b of the hydraulic nut 113, and the hydraulic nut 113 is screwed in so that the piston 113c is located on the most rearward side within the cylinder chamber 113b. Figure 3 (Left side). In this screwed-in state, the push plate portion 113e of the piston 113c is in contact with the end face of the front end side of the outer nested cylinder 112.

[0077] After the tightening of the hydraulic nut 113 is completed, the lever 121b of the aforementioned manual pump 121 is moved up and down to deliver working oil into the cylinder chamber 113b of the hydraulic nut 113. As a result, the piston 113c is propelled forward by the hydraulic pressure within the cylinder chamber 113b. Figure 3 Driven to the right side and the base end side of the screw shaft 2, the outer nested cylinder 112 is moved towards the front screw element 3S side ( Figure 3 (on the right side) is pushed. Thus, multiple screw elements 3 are clamped together at the stepped surface 2a between the outer nested cylinder 112 and the aforementioned screw shaft 2 (only on the right side). Figure 1 The components (represented in the middle) are compressed axially. As a result, an axial gap δ (refer to) is generated between the protruding large-diameter portion 24b of the fixing nut 24 and the front end screw element 3S. Figure 4 ).

[0078] Figure 4 It represents the state in which the gap was generated. Figure 3 A corresponding diagram. In this state, the operator inserts the tightening tool 116 (see reference 112a) through the opening 112a. Figure 5 Insert it radially inside the outer nesting cylinder 112, and tighten the fixing nut 24 by means of the tightening tool 116.

[0079] Figure 5 This indicates the engagement state between the tightening tool 116 and the fixing nut 24 when the tightening tool 116 is used to screw in the fixing nut 24. Figure 3 The diagram is equivalent to the V-V line cross section.

[0080] As shown in the figure, the tightening tool 116 is, for example, a rod-shaped component with a circular cross-section. When the operator screws in the fixing nut 24, the tightening tool 116 is inserted through the opening 112a of the outer nesting cylinder 112, with its front end inserted into the aforementioned through hole 24c formed on the peripheral wall of the fixing nut 24. In this state, the operator holds the portion of the tightening tool 116 that is outside the outer nesting cylinder 112 and directs it towards... Figure 5 Rotate clockwise. This allows the operator to screw in the fixing nut 24 even from the outside of the outer nesting cylinder 112. Then, the operator screws in the fixing nut 24 until the protruding large diameter portion 24b of the fixing nut 24 (see reference). Figure 4 The end face of the base end of the screw element 3S abuts against the end face of the front end of the screw element 3S (i.e., until the gap δ disappears).

[0081] Thus, after the gap δ between the fixing nut 24 and the front screw element 3S disappears, it returns to... Figure 3 In this state, the operator again uses manual pump 121 to supply working oil to cylinder chamber 113b of hydraulic nut 113. This, in turn, causes piston 113c to... Figure 3Advancing to the right, a gap δ is formed again between the front screw element 3S and the fixing nut 24 (refer to...). Figure 4 Therefore, the operator uses tightening tool 116 to screw in the fixing nut 24 until the gap δ disappears.

[0082] Then, the operator repeatedly and alternately performs the operation of supplying hydraulic pressure to the hydraulic nut 113 using the aforementioned manual pump 121 and the operation of tightening the fixing nut 24 using the tightening tool 116 until the pressure measured by the pressure gauge 123 (the value displayed on the display) reaches the preset set pressure. In this way, the tightening operation of the fixing nut 24 can be performed while the multiple screw elements 3 are pushed towards the base end side of the screw shaft 2 by the hydraulic pressure supplied to the hydraulic nut 113 (while being pushed towards the step surface 2a side). As a result, a predetermined surface pressure can be applied between the multiple screw elements 3.

[0083] Thus, after the pressure measured by the pressure gauge 123 becomes the aforementioned set pressure, the shaft mounting clamp 110 is removed from the front end side shaft portion 23 of the screw shaft 2, and the aforementioned spacer 25 and cover 26 (see reference) are removed in place of the shaft mounting clamp 110. Figure 2 It is installed on the screw shaft 2.

[0084] [Effects]

[0085] As explained above, in this embodiment, the screw element fixing clamp 100 includes: an outer nesting cylinder 112, which is externally fitted onto the outer peripheral surface of the fixing nut 24 and abuts against the end face of the front screw element 3S on the radially outer side of the fixing nut 24; a hydraulic nut 113; and a mounting male threaded shaft portion 111, which has an outer peripheral surface with a male threaded portion 111d for the hydraulic nut, and is coaxially mounted to the mixing screw 1 at the end of the mixing screw 1 on the front end side (in this embodiment, for example, the end of the front end side shaft portion 23). The hydraulic nut 113 includes a nut body portion 113a that is threadedly engaged with the outer peripheral surface of the mounting male threaded shaft portion 111, a cylinder chamber 113b formed in the nut body portion 113a, and a piston 113c that is hydraulically driven by the cylinder chamber 113b to push the outer nesting cylinder 112 toward the front screw element 3S. Furthermore, the outer nesting cylinder 112 has an opening 112a formed radially through it, through which a tightening tool 116 for rotating the aforementioned fixing nut 24 about its axis is inserted.

[0086] According to this structure, deviations in the surface pressure applied to each screw element 3 when fixing multiple screw elements 3 to the screw shaft 2 can be suppressed. Specifically, as described above, by supplying working oil to the cylinder chamber 113b of the hydraulic nut 113 using a hydraulic pump or the like (in this embodiment, a manual pump 121), the piston 113c of the hydraulic nut 113 pushes the outer nesting cylinder 112 towards the front screw element 3S. As a result, the multiple screw elements 3 are compressed axially between the outer nesting cylinder 112 and the stepped surface 2a of the aforementioned screw shaft 2. As a result, an axial gap δ is generated between the front screw element 3S and the fixing nut 24 (fixing component). Therefore, by having the operator tighten the fixing nut 24 with this gap δ as an indicator to fill the gap δ, over-tightening or under-tightening of the fixing nut 24 can be prevented, and the surface pressure between each screw element 3 can be uniformly and adequately ensured without relying on the operator's force. Therefore, deformation and thread crushing of the screw element 3 caused by over-tightening of the fixing nut 24 can be prevented, and the decrease in surface pressure between the screw elements 3 caused by under-tightening of the fixing nut 24 can be prevented. Furthermore, according to the aforementioned structure, an opening 112a is formed in the outer nesting cylinder 12 for inserting a tightening tool 116 that rotates the fixing nut 24 about its axis, so the aforementioned tightening operation of the fixing nut 24 can be easily performed even from the outside of the outer nesting cylinder 112. Moreover, in the example of the above embodiment, the hydraulic supply to the hydraulic nut 113 and the tightening operation of the fixing nut 24 are performed alternately over multiple times, so the axial compressive load applied between the multiple screw elements 3 can be increased in stages. Therefore, the problems of under-tightening and over-tightening of the fixing nut 24 can be prevented more reliably.

[0087] Furthermore, in this embodiment, the screw element fixing clamp 100 also includes: a hydraulic pump (in this embodiment, a manual pump 121) connected to the cylinder chamber 113b of the hydraulic nut 113, capable of supplying hydraulic pressure to the cylinder chamber 113b to advance the piston 113c; and a pressure gauge 123 that measures and displays the hydraulic pressure of the working oil supplied to the cylinder chamber 113b.

[0088] According to this structure, the operator can observe the displayed value of the pressure gauge 123 and adjust the operation of the hydraulic pump so that the amount of hydraulic pressure supplied to the hydraulic nut 113 is a preset value. This allows for precise management of the axial compressive load imposed on the multiple screw elements 3 by the hydraulic nut 113. Furthermore, it prevents surface pressure deviation between the screw elements 3 after the fixing nut 24 is tightened.

[0089] Furthermore, in this embodiment, the opening 112a of the aforementioned outer nesting cylinder 112 is formed by an elongated hole that extends in the circumferential direction.

[0090] According to this structure, when screwing in the fixing nut 24, the tightening tool 116, which is inserted into the opening 112a, can be easily rotated in the circumferential direction. Therefore, the screwing in of the fixing nut 24 can be performed easily. Furthermore, by rotating the tightening tool 116 within a defined angular range from one end of the opening 112a to the other in the circumferential direction, over-tightening of the fixing nut 24 can be prevented.

[0091] Furthermore, in this embodiment, the aforementioned outer nesting cylinder 112 has a plurality of the aforementioned openings 112a; the aforementioned plurality of openings 112a are formed at intervals in the circumferential direction of the outer nesting cylinder 112.

[0092] According to this structure, by forming multiple openings 112a at intervals in the circumferential direction in the outer nesting cylinder 112, the insertion part of the tightening tool 116 is not limited to one part compared with the case where only one opening 112a is formed, and the operability of the tightening nut 24 during the tightening operation is improved accordingly.

[0093] Furthermore, in this embodiment, the aforementioned hydraulic pump is a manual pump 121 that sprays working oil manually.

[0094] According to this structure, even in situations where hydraulic pumps are not installed in factory work areas, operators can supply hydraulic pressure to the hydraulic nut 113 using an easily portable manual pump 121. Thus, hydraulic pressure can be supplied to the hydraulic nut 113 without the use of large-scale equipment, simplifying the operation.

[0095] Furthermore, in this embodiment, a female threaded hole 21b that opens to the front end is formed in the axial center of the front end side shaft portion 23 of the screw shaft 2; the aforementioned mounting male threaded shaft portion 111 has: a first male threaded shaft portion 111a, including an outer peripheral surface in which a male threaded portion 111d for a hydraulic nut is formed; and a second male threaded shaft portion 111b, which is connected to the base end side of the first male threaded shaft portion 111a and threadedly engaged with the aforementioned female threaded hole 21b.

[0096] According to this structure, the mounting male threaded shaft portion 111 can be easily installed on the front end side shaft portion 23 of the screw shaft 2. That is, according to this structure, by threading the second male threaded shaft portion 111b of the mounting male threaded shaft portion 111 with the female threaded hole 21b formed in the front end side shaft portion 23 of the screw shaft 2 (more specifically, the axial portion of the first male threaded shaft portion 23a of the front end side shaft portion 23), the mounting male threaded shaft portion 111 can be easily installed on the front end side shaft portion 23 of the screw shaft 2.

[0097] Furthermore, in this embodiment, the screw element fixing clamp 100 also includes a fastening head 114, which is rotatably and integrally mounted relative to the first male threaded shaft portion 111a on which the male threaded shaft portion 111 is mounted. The fastening head 114 has: a connecting plate portion 114a, which is rotatably and integrally connected to the end face of the front end side of the first male threaded shaft portion 111a; and a hexagonal head 114b (an example of a protruding engagement portion), which protrudes from the surface of the connecting plate portion 114a opposite to the surface connected to the first male threaded shaft portion 111a, and can engage with a tightening tool 116 used to rotate the fastening head 114 about its axis.

[0098] According to this structure, the operator can screw in the male threaded shaft portion 111 using the fastening head 114, so that the male threaded shaft portion 111 can be easily and securely assembled onto the front end side shaft portion 23 of the screw shaft 2 without loosening.

[0099] Furthermore, in this embodiment, the aforementioned screw shaft 2 includes: a screw shaft body 21, which is splinedly connected to the aforementioned screw element 3; and a front end side shaft portion 23, which is coaxially connected to the aforementioned screw shaft body 21 and separately at the aforementioned front end side end of the aforementioned screw shaft body 21, and is thinner than the aforementioned screw shaft body 21; the aforementioned front end side shaft portion 23 has the aforementioned male thread portion 23d for fixing nut on its outer peripheral surface.

[0100] According to this structure, the screw shaft body 21 does not constitute the male threaded portion 23d for fixing the nut, which correspondingly allows the axial length of the material used for the screw shaft body 21 to be shortened. Furthermore, as a separate part from the screw shaft body 21, only the front end side shaft portion 23, which is thinner than the screw shaft body 21, needs to be purchased, thus avoiding the waste of cost associated with purchasing materials that are thicker than required. Therefore, compared to manufacturing the mixing screw 1 by incorporating the male threaded portion 23d for fixing the nut as part of the screw shaft body 21, the mixing screw 1 can be manufactured more cheaply.

[0101] Furthermore, the screw element fixing structure 200 of this embodiment includes the aforementioned screw element fixing clamp 100, the aforementioned front end side shaft portion 23 of the mixing screw 1, and the aforementioned fixing nut 24. Thus, the same functional effects as the structures described above can be obtained.

[0102] (Other implementation methods)

[0103] The screw element fixing clamp 100 of the present invention has been described above, but the present invention is not limited thereto. For example, the following modified embodiments may be adopted.

[0104] (1) In the aforementioned embodiment, the front end side shaft portion 23 of the screw shaft 2 is constructed using another component of the screw shaft body 21, but it is not limited to this and may also be integrally formed with the screw shaft body 21.

[0105] (2) In the foregoing embodiments, an example of applying the mixing screw 1 to an extruder has been described, but the use of the mixing screw 1 is not limited to this and can be any other use.

[0106] (3) In the foregoing embodiments, the screw element fixing fixture 100 includes a shaft mounting fixture 110 and a hydraulic supply fixture 120, but it is not necessary to include the hydraulic supply fixture 120. That is, the hydraulic supply fixture 120 can also be a hydraulic supply device pre-installed in a factory or the like.

[0107] (4) In the foregoing embodiments, the screw element fixing clamp 100 includes a fastening head 114, but is not limited thereto, and the fastening head 114 may also be omitted.

[0108] (5) In the above embodiments, the hydraulic supply to the hydraulic nut 113 and the screwing in of the fixing nut 24 are performed alternately multiple times, but it is not limited to this and can also be performed only once.

[0109] Explanation of reference numerals in the attached figures

[0110] 1: Mixing screw

[0111] 2: Screw shaft

[0112] 2a: Step difference surface

[0113] 3: Screw element

[0114] 3S: Front-end screw element

[0115] 21: Screw shaft body

[0116] 21b: Female threaded hole

[0117] 23: Front side shaft section

[0118] 23a: First male thread shaft portion

[0119] 24: Fixing nuts

[0120] 100: Fixture for fixing screw components

[0121] 110: Shaft mounting fixtures

[0122] 111: Install the male threaded shaft.

[0123] 111a: First male thread shaft portion

[0124] 111b: Second male threaded shaft portion

[0125] 111d: Male threaded part for hydraulic nuts

[0126] 112: Outer nested tube

[0127] 112a: Opening

[0128] 113: Hydraulic Nut

[0129] 113a: Nut body

[0130] 113b: Cylinder chamber

[0131] 113c: Piston

[0132] 114: Fastening head

[0133] 114a: Connecting plate section

[0134] 114b: Hexagonal head (protruding engagement part)

[0135] 116: Tightening tools

[0136] 120: Hydraulic supply clamps

[0137] 121: Manual Pump

[0138] 123: Pressure gauge

[0139] 200: Fixture for fixing screw components

[0140] δ: gap

Claims

1. A clamp for fixing screw elements, used in a mixing screw comprising a screw shaft, a plurality of screw elements, and a fixing member, for fixing the plurality of screw elements by the fixing member, wherein the screw shaft has a stepped surface formed perpendicular to an axis, the plurality of screw elements are fitted into the outer peripheral surface of the screw shaft by spline engagement and are arranged axially adjacent to each other and their axial positions are limited by the stepped surface, and the fixing member clamps and secures the plurality of screw elements between itself and the stepped surface, characterized in that... The aforementioned mixing screw has the following characteristics: The fixing nut, serving as the aforementioned fixing component, abuts against the end face of the frontmost screw element among the aforementioned plurality of screw elements; and The fixing nut has a male threaded portion, which is provided at the end of the aforementioned mixing screw on the side opposite to the aforementioned step face, i.e., the front end side, and is used to thread the aforementioned fixing nut onto the outer circumferential surface. The aforementioned screw element fixing fixture includes: The outer nested cylinder is embedded on the outer circumferential surface of the aforementioned fixing nut, and abuts against the end face of the aforementioned front screw element on the radially outer side of the fixing nut; A hydraulic nut, comprising a nut body, a cylinder chamber formed in the nut body, and a piston driven by working oil supplied to the cylinder chamber to push the aforementioned outer nested cylinder toward the aforementioned front screw element; and The mounting male threaded shaft has a male threaded part for hydraulic nuts on its outer peripheral surface for threaded engagement with the aforementioned hydraulic nuts, and is coaxially mounted with the aforementioned mixing screw at the end of the front end side of the mixing screw. The aforementioned outer nesting cylinder has a radially penetrating opening through which a tool for rotating the aforementioned fixing nut about its axis can be inserted.

2. The clamp for fixing screw components as described in claim 1, characterized in that, It also has: A hydraulic pump, connected to the aforementioned cylinder chamber of the aforementioned hydraulic nut, is capable of supplying working oil to the cylinder chamber to drive the aforementioned piston; and A pressure gauge measures and displays the hydraulic pressure of the working oil supplied to the aforementioned cylinder chamber.

3. The screw element fixing clamp as described in claim 1, characterized in that, The aforementioned opening of the outer nested cylinder is formed by an elongated hole that extends in the circumferential direction.

4. The clamp for fixing screw components as described in any one of claims 1 to 3, characterized in that, The aforementioned outer nested cylinder has multiple aforementioned openings; Multiple openings are formed by spacing them apart in the circumferential direction of the aforementioned outer nested cylinder.

5. The screw element fixing clamp as described in claim 2, characterized in that, The aforementioned hydraulic pump is a manual pump that sprays out working oil manually.

6. The clamp for fixing a screw element as described in any one of claims 1 to 3, characterized in that, At the axial center of the aforementioned front end side of the aforementioned mixing screw, an internal threaded hole that opens toward the aforementioned front end side is formed; The aforementioned mounting male threaded shaft portion has: a first male threaded shaft portion, including an outer peripheral surface on which the aforementioned male threaded portion for hydraulic nuts is formed; and a second male threaded shaft portion, which is connected to the base end side of the first male threaded shaft portion and threadedly engaged with the aforementioned female threaded hole.

7. The screw element fixing clamp as described in claim 6, characterized in that, It also has a fastening head, which is rotatably and integrally mounted relative to the aforementioned first male threaded shaft portion for mounting the aforementioned male threaded shaft portion; The aforementioned fastening head has: a connecting plate portion that is rotatably and integrally connected to the end face of the aforementioned front end side of the aforementioned first male threaded shaft portion; and a protruding engaging portion that protrudes from the surface of the connecting plate portion opposite to the surface connected to the aforementioned first male threaded shaft portion, and is capable of engaging with a tool used to rotate the fastening head about its axis.

8. The clamp for fixing screw components as described in claim 1, characterized in that, The aforementioned screw shaft includes: a screw shaft body, which is splinedly connected to the aforementioned screw element; and a front end side shaft portion, which is coaxially connected to the aforementioned screw shaft body and separately at the aforementioned front end side end of the aforementioned screw shaft body, and is thinner than the aforementioned screw shaft body; the aforementioned front end side shaft portion has the aforementioned male threaded portion for fixing nut on its outer peripheral surface.

9. A structure for fixing a screw element, characterized in that, It includes the screw element fixing clamp according to any one of claims 1 to 8, the aforementioned male threaded portion of the fixing nut of the aforementioned mixing screw, and the aforementioned fixing nut.

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