WO2018036091A1

WO2018036091A1 - Variable-depth variable-pitch screw rod, method for net-shape forging screw grooves therefor, and forging device therefor

Info

Publication number: WO2018036091A1
Application number: PCT/CN2017/070939
Authority: WO
Inventors: 张连华; 张晖; 马海军
Original assignee: 中聚信海洋工程装备有限公司
Priority date: 2016-08-22
Filing date: 2017-01-12
Publication date: 2018-03-01
Also published as: CN106313478A; CN106313478B

Abstract

A variable-depth variable-pitch screw rod (1), a method for net-shape forging screw grooves (102) therefor, and a forging device therefor. The variable-depth variable-pitch screw (1) comprises screw threads (101) and the screw grooves (102), and the surfaces of the screw threads (101) and the screw grooves (102) are subjected to squeezing flow by means of a hydraulic forging machine (2) to form continuous metal fibers. The method for net-shape forging screw grooves (102) comprises: mounting an upper forging die (5) and a lower forging die (6) in a first step forging die in a guide die sleeve (4) of a forging and pressing device, and carrying out first-stage forging and pressing on a screw rod blank; mounting an upper forging die (5) and a lower forging die (6) in a second step forging die in a guide die sleeve (4), and carrying out second-stage forging and pressing on all the screw grooves (102) starting from the second step; and similarly, mounting an upper forging die (5) and a lower forging die (6) in an X^th step forging die in a guide die sleeve (4), and carrying out X^th stage forging and pressing on all the screw grooves (102) starting from the X^th step. The screw grooves (102) are formed by forging, so that the continuity of material fibers on the surface of a casting blank can be kept, and the structure is compact; moreover, no cutting machining is needed for the net-shape forging, and various performances of the screw rod can be well optimized.

Description

Method and forging device for deepening variable pitch screw and net shape forging screw groove

Technical field

The invention relates to a screw and a manufacturing method thereof, in particular to a screw and a net shape forging a screw groove and a forging device thereof, which are continuously changing pitch and groove depth, and belongs to the technical field of forging type.

Background technique

Screw is an indispensable part of mechanical equipment. It is generally a screw with equal depth and equidistant groove. It is widely used. For example, the drive screw used on the machine tool is used to push the components such as the carriage along the machine track, and some of them are used in the mechanical transmission of the machine tool. These applications are very successful and very effective. However, there are certain problems in some specific fields. For example, plastic extruders, because of the use of isometric deep-screw screws as extrusion rods, often form holes or bubbles in plastic products, resulting in products becoming Product. After exploration and research, it is proved that the screw with the variable depth variable pitch groove can be used as the extrusion rod to effectively solve the above problems. However, the conventional method for making the screw with variable depth and variable pitch groove is very complicated. The second is the screw that cuts the groove, destroys the structure of the continuous fiber on the surface of the blank, and forces the looser material at the center. The greater resistance, so that the screw torsion and wear resistance is seriously reduced, the specific performance is: 1, the requirements of the machine tool is higher; 2, the amount of cutting processing; 3, the skills of the operators are high; The production cycle is long and the processing cost is high. 5. The utilization rate of the material is very low, and more waste is generated. 6. The material performance of the core portion of the screw shaft is poor. In summary, the traditional plastic machine screw cutting processing form does not meet the modern "least energy consumption, the least displacement, the highest material utilization rate, the highest production efficiency, the shortest process flow, the shortest delivery time, the best product quality, production The lowest cost green forging concept. Therefore, designing a screw that deepens the variable pitch groove and a method of making the continuous blank of the original blank on the surface of the screw are urgent problems to be solved.

Summary of the invention

The object of the present invention is to provide a deep-distance variable pitch screw and a net shape forging groove thereof, and a forging device, which aims to improve the screw strength, increase the toughness and wear resistance of the screw by the method, and utilize the forging type. Achieve no cutting, subversive changes in traditional production methods.

In order to achieve the above object, in accordance with one aspect of the present invention, the present invention is embodied in the following technical solutions: a deep-depth variable pitch screw comprising: a thread, a groove, the surface of the thread and the groove being continuous A metal fiber having a surface formed by a squeeze flow.

In a further embodiment, the number of spiral grooves on the screw is N, and the N grooves are sequentially divided into X gradient steps from the first end to the second end of the screw, and each step includes one or more groove grooves. Among any two adjacent steps, the spiral groove depth, the spiral groove width and the helix angle of the groove of the step near the second end are respectively larger than the spiral groove depth and the spiral groove width of the groove of the step near the first end. And the helix angle, where N, X is greater than or equal to 2.

In a further embodiment, the helix angles of the N slots vary uniformly with the gradient steps; or, the helix angles of the N slots vary randomly with the gradient steps. The spiral groove depth, the spiral groove width, and the helix angle of each of the slots in the same step are equal, and the large diameter of the screw is a predetermined value D.

According to another aspect of the present invention, the present invention provides a forging device for preparing a variable pitch variable pitch screw, the screw comprising: a screw, a screw groove, and the number of spiral grooves on the screw is N, from the first end of the screw to The second end divides the N slots into X gradient steps, each step includes one or more slots, and the spiral groove depth of the slot of the step adjacent to the second end of any two adjacent steps The difference of the spiral groove depth of the groove of the step near the first end is a predetermined groove depth difference, and the difference of the spiral groove width of the groove of the step near the second end and the groove of the step near the first end is predetermined The difference in groove width, the difference between the helix angle of the groove of the step near the second end and the helix angle of the groove of the step near the first end is a predetermined angle difference, wherein N, X is greater than or equal to 2, the screw The large diameter is a predetermined value D, and the forging device comprises X step forging dies, wherein each step forging die corresponds to one step of the screw, and each step forging die comprises an upper forging die and a lower forging die, each The upper forging die and the lower forging die in the step forging die are respectively on the axial center plane of the screw A spiral protrusion having the same spiral angle and the same groove width is formed, and the upper forging die and the lower forging die in each step forging die are uniformly provided with an inner cylindrical arc surface having a screw diameter of a predetermined value D, based on The spiral groove depth, the spiral groove width, and the helix angle in the step of the screw corresponding to each step die set the shape of the spiral forging on the upper forging die and the lower forging die in the step forging die.

In a further embodiment, the forging device further comprises a forging press and a guiding die sleeve, each step forging die being separately mountable in the guiding die sleeve, the upper forging die and the lower forging die center in the same step forging die The spiral protrusions on the section are offset from each other by 180° along the spiral angle of the pitch, and the forging press presses the upper forging die and the lower forging die located in the guiding die sleeve through the hammer head, and forging is located at the upper forging die and A screw blank between the lower forging dies.

According to another aspect of the present invention, the present invention provides a deep variable pitch snail using a forging device The method of the rod, the screw comprises: a screw thread, a screw groove, the number of spiral grooves on the screw is N, and the N screw grooves are sequentially divided into X gradient steps from the first end to the second end of the screw, each step Including one or more groove grooves, wherein the spiral groove depth, the spiral groove width and the helix angle of the groove of the step adjacent to the second end of any two adjacent steps are respectively larger than the groove of the step adjacent to the first end a spiral groove depth, a spiral groove width and a helix angle, wherein N, X is greater than or equal to 2, the large diameter of the screw is a predetermined value D, and the forging device comprises X step forging dies, wherein each step forging die corresponds to a step of the screw, each step forging die comprises an upper forging die and a lower forging die, and the upper forging die and the lower forging die in each step forging die respectively have the same spiral in cross section on the axial center plane of the screw The rising angle and the spiral groove of the same groove width, the upper forging die and the lower forging die in each step forging die are also uniformly provided with an inner cylindrical arc surface with a screw diameter of a predetermined value D, corresponding to each step forging die The spiral groove depth, the spiral groove width and the helix angle of the groove in the step of the screw The shape of the spiral forging on the upper forging die and the lower forging die in the step forging die. The method comprises: installing an upper forging die and a lower forging die in a first step forging die in a guiding die sleeve of a forging device, and placing a screw blank heated to a forging temperature on the upper forging die that is mutually engaged And the lower forging die, the first step of forging the screw blank to make N screw grooves on the screw blank; installing the upper forging die and the lower forging die in the second step forging die In the guiding die sleeve of the forging device, the first stage forged screw blank is placed between the upper forging die and the lower forging die which are engaged with each other, and all the grooves from the second step are subjected to the first Two-stage forging; and so on, the upper forging die and the lower forging die in the X-th step forging die are installed in the guiding die sleeve of the forging device, and the screw blanks after the forging of the (X-1) stage are placed on each other. The X-stage forging is performed on all the grooves from the X-th step between the upper forging die and the lower forging die that are engaged.

In a further embodiment, when forging the screw blank at each stage, the screw blank needs to be forged multiple times, after the end of one forging, the screw blank is rotated by a predetermined angle, and the screw blank moves along the axis. A function of the pitch, and then the next forging, and finally forging all the grooves that need to be forged.

In a further embodiment, any step forging die installed in the guiding die sleeve has spiral projections on the central section of the upper forging die and the lower forging die offset from each other by 180° along the spiral angle of the pitch, and A spring is disposed between the forging die and the lower forging die.

The beneficial contribution of the invention is that the screw groove is made of forging, the material of the screw surface is better, the continuity of the material of the surface of the slab is kept and the structure is tight, and the material with good mechanical properties is distributed throughout the whole. The surface of the screw and the net shape forging of the screw groove do not require cutting, so the various properties of the screw are well optimized, and the service life is also greatly improved, because the screw is maintained on the basis of the original precision for a long time. Therefore, it is used in a plastic machine to make the produced material superior and the product performance better.

DRAWINGS

Figure 1 is a front view showing the structure of a deep variable pitch screw of the present invention;

Figure 2 is a front view showing the structure of the forging device of the present invention;

Figure 3 is a cross-sectional structural view of the A-A section of Figure 2;

Figure 4 is a cross-sectional structural view showing a section B-B of Figure 2;

Figure 5 is a schematic left side view of Figure 2;

Figure 6 is a view showing the working state of the forged first step screw groove of the present invention;

Figure 7 is a view showing the working state of the forged second step screw groove of the present invention;

Figure 8 is a view showing the working state of the forged X-th step screw groove of the present invention.

In the drawing: 1 deep variable pitch screw, 101 screw, 102 screw groove, 2 liquid forging machine, 3 hammer head, 4 guide die sleeve, 5 upper forging die, 501 spiral convex shape, 6 lower forging die, 601 spiral convex shape, 7 anvil, 8 springs.

detailed description

The present invention is further explained below in conjunction with the accompanying drawings:

As shown in Figures 1, 2, 3, 4, and 5, the variable pitch screw 1 includes a thread 101 and a groove 102, and the surfaces of the thread 101 and the groove 102 are pushed by the hammer 3 on the liquid forging machine 2. The forging die 5 and the lower forging die 6 are pressed to form a continuous metal fiber.

The spiral groove number of the variable pitch screw 1 of the present invention is N, and the N screw grooves are sequentially divided into X gradient steps from the first end to the second end of the screw 1, and each step includes one or more screw grooves. The spiral groove depth, the spiral groove width, and the helix angle of each of the grooves in the same step are equal. Among any two adjacent steps, the spiral groove depth, the spiral groove width and the helix angle of the step near the second end are respectively larger than the spiral groove depth, the spiral groove width and the helix angle of the step near the first end, wherein N , X is greater than or equal to 2. That is, each step includes one or more grooved grooves, and the difference between the spiral groove depth of the groove of the step near the second end and the groove depth of the groove of the step near the first end of any two adjacent steps The value is the predetermined groove depth difference, close to the second end The difference between the spiral groove width of the stepped groove and the groove of the step near the first end is a predetermined groove width difference, the spiral angle of the groove of the step near the second end and the groove of the step near the first end The difference in the helix angle is the predetermined angle difference.

In one embodiment, in the deepening variable pitch screw 1 of the present invention, the helix angle of the N grooves varies uniformly with the gradual steps. In another embodiment, the helix angles of the N slots vary randomly with the gradient steps.

In the specific embodiment shown in FIG. 1, the large diameter of the screw 1 is D; the number of spiral grooves on the screw is N grooves, and each n groove is a gradient step of a groove depth h and a groove width l, then the entire screw is divided into N/n=X gradient steps, the spiral depth of the first step is h ₁ , the spiral groove width is l ₁ , the pitch is t ₁ , the helix angle is λ ₁ ; the second step is relative to the groove depth of the first step The gradation amount is Δh ₂ (set value), the groove width gradation amount is the elongation Δl ₂ after forging of a single spiral groove in the first step; and so on, the X step is relative to the X-1 step The groove depth gradient amount is Δh _X (set value), and the groove width gradient amount is the elongation amount Δl _X after forging of a single spiral groove in the X-1 step. Thus, the spiral groove depth of the second step is h ₂ = h ₁ + Δh ₂ , the spiral groove width is l ₂ = l ₁ + Δl ₂ , and the helix angle is λ ₂ (λ ₂ > λ ₁ ). And so on, the spiral groove depth of the Xth step is h _X = h _X-1 + Δh _X , the spiral groove width is l _X = l _X-1 + Δl _X , and the helix angle is λ _X (λ _X > λ _X-1 ).

Please refer to FIG. 2, which is a schematic front view of the forging device of the present invention, which can be used to forge the deep-depth variable pitch screw 1 of the present invention. The forging apparatus shown in Fig. 2 includes a hydraulic machine 2, a guide sleeve 4, an anvil 7, and X step forging dies (not labeled).

Referring to FIG. 2, FIG. 3, FIG. 4 and FIG. 5, each step of the screw 1 is provided with a step forging die, and each step forging die is composed of an upper forging die 5 and a lower forging die 6. . The upper forging die 5 and the lower forging die 6 in each step forging die are respectively formed with spiral

convex shapes

501, 601 having the same spiral rising angle and the same groove width in the axial center plane of the screw, and each step forging The upper forging die 5 and the lower forging die 6 in the die are also uniformly provided with an inner cylindrical arc surface having a screw diameter D. Each step forging die can be separately installed in the guiding die sleeve 4, and any step forging die installed in the guiding die sleeve 4, the spiral protrusions on the central section of the upper forging die 5 and the lower forging die 6 are in the inner edge of the pitch The spiral angles are offset from each other by 180°, and a spring is disposed between the upper forging die 5 and the lower forging die 6. The guide bushing 4 is fixed to the anvil 7 below the hammer head 3 of the hydraulic machine 2. The hydraulic press 2 presses the upper forging die 5 and the lower forging die 6 located in the guide die sleeve 4 by the hammer head 3 to forge the screw blank located between the upper die die 5 and the lower die die 6.

Wherein, the shape of the spiral bulge on the upper forging die 5 and the lower forging die 6 in each step forging die, the spiral groove depth, the spiral groove width and the helix angle of the groove in the step corresponding to the step forging die Based on the settings. That is, the spiral groove depth, the spiral groove width and the helix angle of the groove in the gradient step of the screw corresponding to each step forging die are set as the spiral forging on the upper forging die and the lower forging die in the step forging die shape. For example, the

spiral forging shapes

501 and 601 of the upper forging die 5 and the lower forging cross 6 in the first step forging die are formed at the spiral groove depth h ₁ , the spiral groove width l ₁ , and the helix angle λ ₁ are set values. On the basis of; the upper forging die 5 on the second step forging die and the spirally convex shape on the lower forging cross 6 are formed in the spiral groove depth h ₂ = h ₁ + Δh ₂ , and the spiral groove width l ₂ = l ₁ + Δl ₂ , the helix angle is based on λ ₂ ; and so on, the shape of the spiral protrusion on the X-step forging die is formed at the spiral groove depth h _X = h _X-1 + Δh _X , The spiral groove width l _X = l _X-1 + Δl _X and the helix angle is λ _X (λ _X > λ _X-1 ).

Hereinafter, a method of manufacturing a variable depth pitch screw using the forging device shown in FIG. 5 will be specifically described based on FIGS. 6, 7, and 8. The method of the present invention for manufacturing a variable depth pitch screw comprises the following steps.

Step 1. As shown in FIG. 6, the upper forging die 5 and the lower forging die 6 in the first step forging die are mounted in the guiding die sleeve 4, and the guiding die sleeve 4 is fixed on the anvil 7 below the hammerhead 3. , the screw blank is heated to the forging temperature. Wherein, between the upper forging die 5 and the lower forging die 6, a spring 8 is provided, and the

spiral forging shapes

501 and 601 on the central section of the upper forging die 5 and the lower forging die 6 are offset from each other by 180° in the pitch. The rules for installing other step forging dies in the guiding dies 4 are the same, and therefore will not be described below.

Step 2: placing a screw blank heated to the forging temperature between the upper forging die 5 and the lower forging die 6, and performing the first forging on the screw blank to obtain N pieces on the screw blank Screw groove. Preferably, the screw blank is rotated by a predetermined angle, such as 360°, 1°, 5°, etc., and the screw blank is moved along the axis as a function of the pitch, wherein the axial movement distance=guide ÷360×rotation angle, in order Forging the screw blank to obtain N screw grooves.

Step 3 As shown in Fig. 7, the upper forging die 5 and the lower forging die 6 of the second step forging die are mounted in the guiding die sleeve 4, and the guiding die sleeve 4 is fixed to the anvil 7 below the hammerhead 3.

Step 4: placing the first forged spiral blank between the upper forging die 5 and the lower forging die 6, and performing a second forging on all the grooves from the second step. Preferably, the screw blank is rotated by a predetermined angle, such as 360°, 1°, 5°, etc., and the screw blank is moved along the axis as a function of the pitch, wherein the axial movement distance=guide ÷360×rotation angle, in order Forging all the grooves from the second step.

According to the above steps, as shown in Figure 8, the upper forging die 5 and the lower forging in the X-step forging die The mold 6 is installed in the guide die sleeve 4 of the forging device; the first (X-1) forged screw blank is placed between the upper forging die 5 and the lower forging die 6 for the step from the Xth step For all the grooves, the Xth forging is performed.

In summary, the present invention provides a step forging die for each step of the variable pitch variable pitch screw 1, and each step forging die can be separately installed in the guiding die sleeve 4. In this way, the first step forging die can be first installed in the guiding die sleeve 4, and the screw blank is forged for the first time to make N screw grooves on the screw blank, thereby forming a deep variable pitch screw. The first step of 1. Next, the second step forging die is installed in the guiding die sleeve 4, and the second forging is performed on all the grooves on the spiral blank after the first forging from the second step, thereby forming a deepening change. The second step from the screw 1. According to the above steps, all the spiral grooves of the X step are forged in sequence. Thus, the variable depth groove on the screw of the invention is forged, and the material of the screw surface is better, the continuity of the material of the surface of the slab is kept and the structure is tight, and the material with good mechanical properties is distributed throughout the screw. The surface of the groove and the net shape forging do not require cutting, so the various properties of the screw are well optimized, and the service life is also greatly improved, because the screw is kept on the basis of the original accuracy for a long time. Therefore, it is used in a plastic machine to make the produced material excellent and the product performance is better.

It should be noted that any changes to the specific embodiments of the invention will be apparent to those skilled in the art without departing from the scope of the appended claims. Accordingly, the scope of the claims of the invention is not limited to the foregoing specific embodiments.

Claims

A deepening variable pitch screw comprising: a screw thread and a screw groove, characterized in that:

The surface of the screw and the groove is a continuous metal fiber.

The surface of the continuous metal fiber is formed by an extrusion flow.
The variable pitch variable pitch screw according to claim 1, wherein

The number of spiral grooves on the screw is N, and the N screw grooves are sequentially divided into X gradient steps from the first end to the second end of the screw, and each step includes one or more screw grooves.

Among any two adjacent steps, the spiral groove depth, the spiral groove width, and the helix angle of the groove of the step near the second end are respectively larger than the spiral groove depth, the spiral groove width, and the spiral groove of the step near the first end. Spiral angle, where N, X is greater than or equal to 2.
The variable pitch variable pitch screw according to claim 2, wherein

The helix angle of the N grooves varies uniformly with the gradient steps; or

The helix angle of the N slots varies randomly with the gradient steps.
The variable pitch variable pitch screw according to claim 2, wherein

The spiral groove depth, the spiral groove width and the spiral angle of the respective grooves in the same step are equal.

The large diameter of the screw is a predetermined value D.
A forging device for preparing a variable depth variable pitch screw, the screw comprising: a screw thread and a screw groove, wherein the number of spiral grooves on the screw is N, and the N screw grooves are sequentially divided from the first end to the second end of the screw X gradient steps,

Each step includes one or more slots, and the difference between the spiral groove depth of the groove of the step near the second end of any two adjacent steps and the spiral groove depth of the groove of the step near the first end For the predetermined groove depth difference, the difference between the spiral groove width of the groove of the step near the second end and the groove of the step near the first end is a predetermined groove width difference, and the spiral angle of the groove of the step near the second end The difference from the helix angle of the groove of the step near the first end is a predetermined angle difference, wherein N, X is greater than or equal to 2, and the large diameter of the screw is a predetermined value D, characterized in that

The forging device includes X step forging dies, wherein each step forging die corresponds to one step of the screw,

Each step forging die comprises an upper forging die and a lower forging die, and the upper forging die and the lower forging die in each step forging die respectively have the same spiral angle and the same groove width in the axial center plane of the screw. The spiral bulge, the upper forging die and the lower forging die in each step forging die are also uniformly provided with an inner cylindrical arc surface having a screw diameter of a predetermined value D,

The shape of the spiral forging on the upper forging die and the lower forging die in the step forging die is set based on the spiral groove depth, the spiral groove width, and the helix angle in the step of the screw corresponding to each step forging die.
The forging apparatus according to claim 5, further comprising a forging press and a guide die sleeve,

Each step forging die can be separately installed in the guiding die sleeve, and the spiral protrusions on the central section of the upper forging die and the lower forging die in the same step forging die are mutually offset by 180° along the spiral angle of the pitch.

The forging press presses the upper forging die and the lower forging die located in the guide die sleeve by a hammer to forge a screw blank located between the upper forging die and the lower forging die.
A method for manufacturing a variable depth variable pitch screw using a forging device,

The screw comprises: a screw thread and a screw groove, wherein the number of spiral grooves on the screw is N, and the N screw grooves are sequentially divided into X gradient steps from the first end to the second end of the screw, and each step includes one or more a spiral groove, in any two adjacent steps, the spiral groove depth, the spiral groove width and the helix angle of the groove of the step near the second end are respectively larger than the spiral groove depth of the groove of the step adjacent to the first end, a spiral groove width and a helix angle, wherein N, X is greater than or equal to 2, and the large diameter of the screw is a predetermined value D,

The forging device comprises X step forging dies, wherein each step forging die corresponds to one step of the screw, each step forging die comprises an upper forging die and a lower forging die, and the upper forging in each step forging die The die and the lower forging die respectively have spiral protrusions having the same spiral angle and the same groove width on the axial center plane of the screw, and the upper forging die and the lower forging die in each step forging die are uniformly provided with a screw The inner cylindrical arc surface having a large diameter of a predetermined value D, and the upper forging die in the step forging die is set based on the spiral groove depth, the spiral groove width and the helix angle of the screw groove in the step of the screw corresponding to each step forging die The shape of the spiral protrusion on the lower forging die, characterized in that the method comprises:

The upper forging die and the lower forging die in the first step forging die are installed in the guiding die sleeve of the forging device, and the screw blank heated to the forging temperature is placed on the upper forging die and the lower forging die which are mutually engaged Performing a first stage forging of the screw blank to prepare N screw grooves on the screw blank;

The upper forging die and the lower forging die in the second step forging die are installed in the guiding die sleeve of the forging device, and the first stage forged screw blank is placed on the upper forging die and the lower forging die which are mutually engaged For the second stage of forging, for all the slots from the second step;

By analogy, the upper forging die and the lower forging die in the X-th step forging die are installed in the guiding die sleeve of the forging device, and the screw blanks after the forging of the (X-1) stage are placed in the mutually interlocking manner. Between the forging die and the lower forging die, the X-stage forging is performed on all the grooves from the X-th step.
The method of claim 7 wherein:

When forging the screw blank at each stage, the screw blank needs to be forged several times. After the end of one forging, the screw blank is rotated by a predetermined angle, and the screw blank is moved along the axis as a function of the pitch, and then The next forging, the final forging all the grooves required for forging.
The method of claim 8 wherein:

Any step forging die installed in the guiding die sleeve, the spiral protrusions on the central section of the upper forging die and the lower forging die are offset from each other by 180° along the spiral angle of the pitch, and the upper forging die and the lower forging die Springs are provided between them.