A device for drawing horn-like smooth curves

Abstract

The invention discloses a device for drawing a horn-like smooth curve, comprising a T-shaped frame, the T-shaped frame comprising a column and a beam, the column being centrally arranged below the beam; a roller being arranged at the lower end of the column, the axle of the roller being parallel to the beam; a left marking pen and a right marking pen being movably arranged perpendicular to the beam on the beam, the nibs of the left marking pen and the right marking pen being coplanar with the lowest point of the roller, a rotatable winding shaft being arranged on the column, a left pull rope and a right pull rope being wound on the winding shaft, one end of the left pull rope being connected to the winding shaft, and the other end being connected to the left marking pen; one end of the right pull rope being connected to the winding shaft, and the other end being connected to the right marking pen; a transmission being detachably connected to the column, the input shaft of the transmission being connected to the axle, and the output shaft of the transmission being connected to the winding shaft. The device for drawing a horn-like smooth curve of the invention has a simple structure and is easy to use, greatly simplifies the method of drawing two gradual curves, shortens the drawing time, and improves the accuracy of marking.

Description

Technical Field

[0001] The invention relates to the field of drawing tools, and in particular to a device for drawing horn-like smooth curves. Background Art

[0002] In life, we often need to use smooth curves similar to horns. Smooth curves similar to horns include outer curves and inner curves, and the distance between the inner curve and the outer curve gradually approaches. For example, a curved road has two sides gradually approaching each other.

[0003] In the field of mold manufacturing, there is a bull horn gate, which refers to a gate with a smooth curved cone shape like a bull horn, whose cross-sectional size gradually decreases, and the small end is connected to the bottom of the cavity. The bull horn gate is set in a hidden place on the inner surface of the plastic part and does not affect the appearance of the product. If the mold is small, it can be accurately processed by a CNC machining center. However, for molds with particularly large sizes and no CNC machining center that can process them, or single-piece small-batch products, the cost of using a CNC machining center increases dramatically. At this time, two curves can only be drawn manually and then processed manually. Drawing two curves that are gradually approaching is a very troublesome task and requires a lot of energy.

[0004] Therefore, how to design a device that can quickly and accurately draw two curved, gradually approaching smooth curves similar to horns is a technical problem that technicians in this field currently need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the main purpose of the present invention is to provide a device for drawing horn-like smooth curves, which does not require tedious calculations and can accurately and quickly draw two curves that gradually approach the center line.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions.

[0007] A device for drawing a horn-like smooth curve comprises a T-shaped frame, the T-shaped frame comprises a column and a crossbeam, the column is centrally arranged below the crossbeam; a roller is arranged at the lower end of the column, and the wheel axle of the roller is parallel to the crossbeam; a left marking pen and a right marking pen perpendicular to the crossbeam are movably arranged on the crossbeam, and the tips of the left marking pen and the right marking pen are coplanar with the lowest points of the rollers; a rotatable winding shaft is arranged on the column, and a left pull rope and a right pull rope are wound on the winding shaft, one end of the left pull rope is connected to the winding shaft, and the other end is connected to the left marking pen; one end of the right pull rope is connected to the winding shaft, and the other end is connected to the right marking pen; a transmission is detachably connected to the column, the input shaft of the transmission is connected to the wheel axle, and the output shaft of the transmission is connected to the winding shaft.

[0008] Furthermore, a slide groove is arranged on the crossbeam along the length direction of the crossbeam, a left slider matching the slide groove is arranged on the left marking pen, and a right slider matching the slide groove is arranged on the right marking pen.

[0009] Furthermore, a left end cover and a right end cover are respectively provided at the left and right ends of the beam, a left tension spring is connected between the inner surface of the left end cover and the left marking pen, and a right tension spring is connected between the inner surface of the right end cover and the right marking pen.

[0010] Furthermore, a transmission fixing plate is arranged on the column, screw holes are arranged on the fixing plate, and the transmission is connected to the transmission fixing plate by bolts.

[0011] Furthermore, the transmission is a continuously variable transmission or a fixed reduction ratio transmission, and the fixed reduction ratio transmission has a variety of reduction ratio specifications to choose from.

[0012] Furthermore, a first square hole is provided on the end face of the input shaft of the transmission, a first square head matching the first square hole is provided on the wheel axle of the roller, and the first square head is inserted into the first square hole; a second square hole is provided on the end face of the output shaft of the transmission, a second square head matching the second square hole is provided on the winding shaft, and the second square head is inserted into the second square hole.

[0013] Furthermore, the axle of the roller is connected to the input shaft of the transmission through a coupling, and the winding shaft is connected to the output shaft of the transmission through a coupling.

[0014] Furthermore, a scale layer is provided on the crossbeam.

[0015] Furthermore, a left fixed pulley and a right fixed pulley are provided at the intersection of the crossbeam and the column, and a left pull rope is passed around the left fixed pulley, and a right pull rope is passed around the right fixed pulley.

[0016] Furthermore, a handle is provided on the crossbeam.

[0017] The device for drawing a horn-like smooth curve of the present invention has a simple structure and is easy to use, and greatly simplifies the method of drawing two gradually approaching curves. Compared with the method of using a mechanical drawing, the device is easy to operate, does not require complicated and tedious calculations, and greatly shortens the drawing time. In particular, for drawing a curve with an irregular center line, the drawing speed is greatly improved, and the drawn curve has a smooth transition. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0019] Figure 1 It is a horn-like smooth curve with an outer curve and an inner curve;

[0020] Figure 2 A three-dimensional schematic diagram of an embodiment of a device for drawing a horn-like smooth curve according to the present invention;

[0021] Figure 3 It is a three-dimensional exploded view of an embodiment of the device for drawing a horn-like smooth curve of the present invention;

[0022] Figure 4 A longitudinal section view of an embodiment of a device for drawing a horn-like smooth curve according to the present invention;

[0023] Figure 5 A three-dimensional schematic diagram of a T-shaped frame of the device for drawing a horn-like smooth curve according to the present invention;

[0024] Figure 6 A three-dimensional schematic diagram of a transmission of the device for drawing a horn-like smooth curve according to the present invention.

[0025] In the above picture:

[0026] A outer curve; B inner curve; C center line;

[0027] 1 column; 101 transmission fixing plate; 102 screw hole;

[0028] 2 crossbeam; 201 slideway; 202 scale layer; 203 handle;

[0029] 3 roller; 301 first square head; 4 left marking pen; 401 left slider;

[0030] 5 right marking pen; 501 right slider; 6 winding shaft; 601 second square head;

[0031] 7 left pull rope; 8 right pull rope; 9 transmission; 901 first square hole; 902 second square hole;

[0032] 10 left end cover; 11 right end cover; 12 left tension spring; 13 right tension spring;

[0033] 15: left fixed pulley; 16: right fixed pulley. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] In the following description, specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] refer to Figure 1In daily life, we often need to use a horn-like smooth curve, which includes an outer curve A and an inner curve B. The distance between the inner curve B and the outer curve A gradually approaches, and C is the center line of the horn-like smooth curve. For example, a curved road has curbs on both sides gradually approaching each other.

[0037] In the field of mold manufacturing, there is a bull horn gate, which refers to a gate with a smooth curved cone shape like a bull horn, whose cross-sectional size gradually decreases, and the small end is connected to the bottom of the cavity. The advantage of the bull horn gate is that it is located in a hidden place on the inner surface of the plastic part and does not affect the appearance of the product. If the mold is small, it can be accurately processed by a CNC machining center. However, if the mold size is particularly large and there is no CNC machining center that can process it, or if it is a single piece and small batch product, the cost of using a CNC machining center will increase dramatically. At this time, it can only be done by manually drawing two curves and then manually processing them. Drawing two curves that are gradually approaching is a very troublesome thing and requires a lot of energy.

[0038] The invention provides a device for drawing a horn-like smooth curve, which can quickly draw the outer curve and the inner curve of the horn-like smooth curve.

[0039] refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 A device for drawing a horn-like smooth curve comprises a T-shaped frame, which comprises a column 1 and a beam 2, wherein the column 1 is centrally arranged below the beam 2; a roller 3 is arranged at the lower end of the column 1, and the axle of the roller 3 is parallel to the beam 2; a left marking pen 4 and a right marking pen 5 perpendicular to the beam 2 are movably arranged on the beam 2, and the tips of the left marking pen 4 and the right marking pen 5 are coplanar with the lowest point of the roller 3; a rotatable winding shaft 6 is arranged on the column 1, and a left pull rope 7 and a right pull rope 8 are wound on the winding shaft 6, one end of the left pull rope 7 is connected to the winding shaft 6, and the other end is connected to the left marking pen 4; one end of the right pull rope 8 is connected to the winding shaft 6, and the other end is connected to the right marking pen 5; a transmission 9 is detachably connected to the column 1, the input shaft of the transmission 9 is connected to the axle, and the output shaft of the transmission 9 is connected to the winding shaft 6.

[0040] In the above embodiment, the roller 3 rotates, driving the input shaft of the transmission 9 to rotate, the output shaft of the transmission 9 drives the winding shaft 6 to rotate, the winding shaft 6 pulls the left pull rope 7 and the right pull rope 8, and the left marking pen 4 and the right marking pen 5 move relatively close to each other at the same time. When the track of the roller 3 is a straight line, the left marking pen 4 and the right marking pen 5 draw two straight lines symmetrical about the track of the roller 3 and gradually approach the track of the roller 3; when the track of the roller 3 is a curve, the left marking pen 4 and the right marking pen 5 will draw two curves that gradually approach each other.

[0041] Furthermore, the crossbeam 2 is provided with a slide groove 201 along the length direction of the crossbeam 2 , the left marking pen 4 is provided with a left slider 401 matching the slide groove 201 , and the right marking pen 5 is provided with a right slider 501 matching the slide groove 201 .

[0042] In the above embodiment, a slide groove 201 is set on the beam 2, and sliders are set on the left marking pen 4 and the right marking pen 5, which can ensure that the left marking pen 4 and the right marking pen 5 move perpendicular to the beam 2 and also ensure that the left marking pen 4 and the right marking pen 5 move on the beam 2 relatively smoothly.

[0043] Furthermore, a left end cover 10 and a right end cover 11 are respectively provided at the left and right ends of the beam 2. A left tension spring 12 is connected between the inner surface of the left end cover 10 and the left marking pen 4, and a right tension spring 13 is connected between the inner surface of the right end cover 11 and the right marking pen 5.

[0044] In the above embodiment, a left end cap 10 and a right end cap 11 are respectively arranged at the left and right ends of the crossbeam 2, a left tension spring 12 is arranged between the left end cap 10 and the left marking pen 4, and a right tension spring 13 is arranged between the right end cap 11 and the right marking pen 5, so as to ensure that the left pull rope 7 or the right pull rope 8 is not loose, and the left marking pen 4 or the right marking pen 5 is in the correct position. When the drawing is finished, the left marking pen 4 and the right marking pen 5 can also be reset.

[0045] Furthermore, a transmission fixing plate 101 is provided on the column 1 , screw holes 102 are provided on the fixing plate, and the transmission 9 is connected to the transmission fixing plate 101 by bolts.

[0046] In the above embodiments, a transmission fixing plate 101 with screw holes 102 is provided on the column 1, and the transmission 9 can be detachably connected by bolts, so that the transmission 9 can be replaced.

[0047] Furthermore, the transmission 9 is a continuously variable transmission or a fixed reduction ratio transmission, and the fixed reduction ratio transmission has a variety of reduction ratio specifications to choose from.

[0048] The speed reduction ratio determines the relative movement speed of the left marking pen 4 or the right marking pen 5. A high speed reduction ratio means a fast movement speed, while a low speed reduction ratio means a slow movement speed. In the above embodiments, if a continuously variable transmission is selected, the relative movement speed of the left marking pen 4 or the right marking pen 5 can be adjusted at will, making it more flexible to use. If a fixed speed reduction ratio reducer is selected, a reducer with a suitable speed reduction ratio is selected according to the needs and installed on the transmission fixing plate 101.

[0049] For further reference, Figure 6A first square hole 901 is provided on the end face of the input shaft of the transmission 9, a first square head 301 matching the first square hole 901 is provided on the axle of the roller 3, and the first square head 301 is inserted into the first square hole 901; a second square hole 902 is provided on the end face of the output shaft of the transmission 9, a second square head 601 matching the second square hole 902 is provided on the winding shaft 6, and the second square head 601 is inserted into the second square hole 902.

[0050] The above embodiment is a connection method between the input shaft of the transmission 9 and the wheel axle, and the output shaft of the transmission 9 and the winding shaft 6. A first square head 301 is set on the wheel axle, a square hole is set on the input shaft of the transmission 9, a second square head 601 is set on the winding shaft 6, and a second square hole 902 is set on the output shaft of the transmission 9 to achieve quick connection.

[0051] Furthermore, the axle of the roller 3 is connected to the input shaft of the transmission 9 via a coupling, and the winding shaft 6 is connected to the output shaft of the transmission 9 via a coupling.

[0052] In the above embodiments, preferably, the wheel axle and the input shaft of the transmission 9, and the winding shaft 6 and the output shaft of the transmission 9 can also be connected through a coupling.

[0053] Furthermore, a scale layer 202 is provided on the crossbeam 2 .

[0054] In the above embodiment, a scale layer 202 is provided on the beam 2, so that the moving distances of the left marking pen 4 and the right marking pen 5 can be more intuitively seen. The scale layer 202 can be a scale line printed on the beam 2, or a scale ruler can be pasted on the beam 2.

[0055] Furthermore, a left fixed pulley 15 and a right fixed pulley 16 are provided at the intersection of the crossbeam 2 and the column 1 , and the left pull rope 7 is passed around the left fixed pulley 15 , and the right pull rope 8 is passed around the right fixed pulley 16 .

[0056] In the above embodiments, in order to prevent the left and right cables from rubbing against each other at the intersection of the beam 2 and the column 1, a left fixed pulley 15 and a right fixed pulley 16 are arranged at the intersection of the beam 2 and the column 1, which can greatly extend the service life of the left and right cables.

[0057] Furthermore, in order to facilitate manipulation, a handle 203 is provided on the beam 2 , and the handle 203 is located on the side of the middle portion of the beam 2 .

[0058] For example, the following is a picture Figure 1 Taking the bull horn-like smooth curve shown in the figure as an example, the method of using the device for drawing a bull horn-like smooth curve is demonstrated.

[0059] Request to make Figure 1The bull-horn-like smooth curve includes an outer curve A and an inner curve B. C is the center line of the bull-horn-like smooth curve. The center line is a quarter arc of a circle with a diameter of 637mm. At the starting end of the bull-horn-like smooth curve, the distance between the outer curve and the inner curve is 100mm. At the end of the bull-horn-like smooth curve, the distance between the outer curve and the inner curve is 40mm.

[0060] The first step is to calculate the reduction ratio;

[0061] Let L be the length of the arc of the center line, D be the diameter of the circle where the center line is located, and S be the distance moved by the left or right marking pen, then:

[0062] L=1 / 4πD=1 / 4π×637≈500.045mm

[0063] S = 1 / 2 × 100-1 / 2 × 40 = 30 mm

[0064] i=500.045÷30≈16.668, rounding i=17.

[0065] The second step is to select a fixed reduction ratio reducer with a reduction ratio i=17 and install it on the reducer fixing plate;

[0066] Step 3: Draw the center line;

[0067] The fourth step is to hold the handle, make the column perpendicular to the ground, make the roller in the same direction as the starting point of the center line, and push along the center line until the roller rolls to the end point of the center line. The left and right marking pens draw the outer curve A and the inner curve B. The horn-like smooth curve drawing device of the present invention has a simple structure, is easy to use, and can draw lines accurately, which greatly simplifies the method of drawing a line close to another curve. Obviously, the horn-like smooth curve drawing device of the present invention can also draw curves with irregular center line tracks, such as S-shaped and wavy shapes. Compared with the mechanical drawing method, this device has a simple structure, does not require complex and cumbersome calculations, and greatly shortens the drawing time.

[0068] Although the present invention has been described in detail in this specification by means of general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto on the basis of the present invention. Therefore, these modifications or improvements made without departing from the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A device for drawing smooth curves like horns, It is characterized in that The invention comprises a T-shaped frame, wherein the T-shaped frame comprises a column (1) and a crossbeam (2), wherein the column (1) is centrally arranged below the crossbeam (2); a roller (3) is arranged at the lower end of the column (1), and the axle of the roller (3) is parallel to the crossbeam (2); a left marking pen (4) and a right marking pen (5) perpendicular to the crossbeam (2) are movably arranged on the crossbeam (2), and the tips of the left marking pen (4) and the right marking pen (5) are coplanar with the lowest point of the roller (3); and a roller (3) is arranged on the column (1). A rotatable winding shaft (6) is provided, and a left pull rope (7) and a right pull rope (8) are wound on the winding shaft (6), one end of the left pull rope (7) is connected to the winding shaft (6), and the other end is connected to the left marking pen (4); one end of the right pull rope (8) is connected to the winding shaft (6), and the other end is connected to the right marking pen (5); a transmission (9) is detachably connected to the column (1), the input shaft of the transmission (9) is connected to the wheel axle, and the output shaft of the transmission (9) is connected to the winding shaft (6).

2. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that The crossbeam (2) is provided with a slide groove (201) along the length direction of the crossbeam (2), the left marking pen (4) is provided with a left sliding block (401) matching the slide groove (201), and the right marking pen (5) is provided with a right sliding block (501) matching the slide groove (201).

3. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that The left and right ends of the crossbeam (2) are respectively provided with a left end cover (10) and a right end cover (11); a left tension spring (12) is connected between the inner surface of the left end cover (10) and the left marking pen (4); and a right tension spring (13) is connected between the inner surface of the right end cover (11) and the right marking pen (5).

4. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that A transmission fixing plate (101) is arranged on the column (1), screw holes (102) are arranged on the fixing plate, and the transmission (9) is connected to the transmission fixing plate (101) via bolts.

5. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that The transmission (9) is a continuously variable transmission or a fixed reduction ratio transmission, and the fixed reduction ratio transmission has a variety of reduction ratio specifications to choose from.

6. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that The transmission (9) is provided with a first square hole (901) on the end face of the input shaft, the roller (3) is provided with a first square head (301) matching the first square hole (901) on the axle, and the first square head (301) is inserted into the first square hole (901); the transmission (9) is provided with a second square hole (902) on the end face of the output shaft, the winding shaft (6) is provided with a second square head (601) matching the second square hole (902), and the second square head (601) is inserted into the second square hole (902).

7. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that The wheel axle of the roller (3) is connected to the input shaft of the transmission (9) via a coupling, and the winding shaft (6) is connected to the output shaft of the transmission (9) via a coupling.

8. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that A scale layer (202) is provided on the crossbeam (2).

9. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that A left fixed pulley (15) and a right fixed pulley (16) are provided at the intersection of the crossbeam (2) and the column (1), and the left pull rope (7) is passed around the left fixed pulley (15), and the right pull rope (8) is passed around the right fixed pulley (16).

10. The device for drawing a horn-like smooth curve according to claim 1, It is characterized in that A handle (203) is provided on the crossbeam (2).

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