Archery arrowhead with a spiral groove

Abstract

The present invention relates to a measuring device for precisely measuring the straightness and concentricity of an arrow and an arrow sorting system using the same. The measuring device of the present invention includes a base, a first support, a second support, a bearing structure, an LM guide moving structure, and a dial gauge measuring part. The first support and the second support support both ends of the arrow, and the bearings installed on each support allow the arrow to rotate smoothly. The support is configured to be movable using LM guides and LM blocks, so as to accommodate arrows of various lengths, and can be fixed at a desired position using a position fixing device. The dial gauge measuring unit contacts the outer surface of the arrow to quantitatively measure straightness and concentricity by measuring the displacement caused by the arrow's rotation. The measured values ​​can be used to evaluate the quality of the arrows and can be sorted by grade by comparing them with standard values. In addition, the present invention can be applied to a production line to automatically or manually inspect the straightness and concentricity of arrows and to select acceptable and unacceptable products based on the measurement results. According to the present invention, the quality of arrows can be evaluated objectively and quantitatively, and can contribute to improving the quality of competition arrows and high-precision arrows and increasing production efficiency.

Description

Technology Field

[0001] The present invention relates to an arrowhead for archery, and more specifically, to an arrowhead for archery in which a helical flute is formed on the outer surface of the arrowhead to improve flight stability, rotational stability, and aerodynamic characteristics. Background Technology

[0002] General archery arrowheads are manufactured with a conical or bullet-shaped exterior and have a smooth outer surface.

[0003] However, with such conventional arrowheads, the airflow during flight is simply formed along the outer surface of the arrowhead, which limits the improvement of rotational stability, and hitting precision may decrease if the flight attitude is unstable.

[0004] Furthermore, since the flight stability of the arrow is primarily secured by the rear vane, the aerodynamic function of the arrowhead itself is not fully utilized.

[0005] Therefore, there is a need for technology that can control airflow and improve the flight stability of the arrow by improving the shape of the arrowhead itself. The problem to be solved

[0006] The present invention has been devised to solve the above-mentioned problems, and

[0007] A spiral groove is formed on the outer surface of the arrowhead.

[0008] Control airflow and

[0009] Improving flight stability

[0010] Improve rotational stability and

[0011] Improving hit accuracy

[0012] The purpose is to provide arrowheads for archery. means of solving the problem

[0013] composition

[0014] An archery arrowhead according to one embodiment of the present invention

[0015] An arrowhead body with a formed tip, and

[0016] It includes at least one spiral groove (Flute) formed on the outer surface of the above arrowhead body.

[0017] The above spiral groove can be formed to have a constant twist angle while extending along the length direction of the arrowhead.

[0018] The number of the spiral grooves mentioned above is

[0019] 2

[0020] 3

[0021] 4

[0022] It can be formed from one or more of the following.

[0023] In addition, the grooves can be arranged at equal intervals, and

[0024] In the case of two grooves, 180°,

[0025] For 3 grooves, 120°,

[0026] 90° for 4 grooves

[0027] It can be arranged at intervals.

[0028] The spiral groove mentioned above can be formed in a right-turn or left-turn direction. Effects of the invention

[0029] According to the present invention

[0030] ① Can control airflow around the arrowhead.

[0031] ② It can improve the rotational stability of the arrow.

[0032] ③ It can reduce attitude shaking during flight.

[0033] ④ It can improve hit accuracy.

[0034] ⑤ A unique appearance can be realized. Brief explanation of the drawing

[0035] . Specific details for implementing the invention

[0036] 1. Overall Structure

[0037] This is a description of the overall configuration. This device measures the displacement of a dial gauge while rotating an arrow shaft that has been seated on bearings installed on two supports. The measured values ​​are used as a standard to evaluate the degree of bending, straightness, runout, and concentricity of the arrow. Additionally, by adjusting the position of the supports along the LM guide, it can accommodate arrows of various lengths and maintain consistent conditions during repeated measurements.

[0038] 2. Support structure

[0039] The support of the present invention is a structure configured to stably support both ends of an arrow while allowing it to rotate.

[0040] The support consists of a first support and a second support, each placed at regular intervals on the base. The distance between the two supports can be formed to be adjustable according to the length of the arrow to be measured.

[0041] A bearing supporting the arrow shaft is installed at the top of each support. The bearing contacts the outer surface of the arrow, allowing it to rotate freely with minimal friction.

[0042] The bearings may consist of one or more pairs and support the arrow to prevent it from slipping out during measurement through a V-shape or parallel arrangement structure.

[0043] The support can include a height adjustment function, allowing it to accommodate arrows of various diameters. Additionally, the position of the support is configured to move along an LM guide or a slide structure, allowing for adjustment of the spacing according to the length of the arrow.

[0044] The support can be made of aluminum, steel, or other materials with excellent rigidity, and is designed to minimize vibrations or shaking that may occur during measurement.

[0045] With this support structure, the arrow rotates stably during the measurement process, and the accuracy of straightness and thimble measurements using a dial gauge can be improved.

[0046] 3. Bearing Structure

[0047] The bearing structure of the present invention is configured to enable free rotation while stably supporting the arrow shaft.

[0048] The bearing structure may consist of a first bearing and a second bearing, and each bearing is rotatably installed on the upper part of the support.

[0049] The above bearings can be arranged at a certain angle to each other so that the arrow shaft naturally settles at the center position. Preferably, two bearings are arranged to form a V-shape to support the outer surface of the arrow from both sides.

[0050] The outer ring of the bearing is in direct contact with the arrow shaft, while the inner ring is fixed to the axis of rotation. Accordingly, when the arrow is rotated manually or by an automatic drive mechanism, the bearing rotates together to minimize frictional resistance.

[0051] The bearing may be a ball bearing, a miniature bearing, or a precision bearing, and may be formed with a low-friction structure to improve rotational precision.

[0052] In addition, the bearing spacing can be configured to be adjustable, allowing it to accommodate arrow shafts of different diameters.

[0053] A urethane, rubber, or synthetic resin coating layer may be formed on the outer surface of the bearing to prevent damage to the arrow surface and inhibit slipping.

[0054] With the above bearing structure, the arrow is stably supported in the axial direction while rotating smoothly, and the straightness, degree of bending, and precision of thimble measurement by the dial gauge can be improved.

[0055] 4. LM Guide Movement Structure

[0056] The LM guide moving structure of the present invention is configured to precisely adjust the position of the support so as to measure arrows of various lengths.

[0057] The LM guide moving structure consists of an LM guide installed on a base, an LM block that moves along the LM guide, and a support member coupled to the LM block.

[0058] The LM guide is installed along the length of the base, and the LM block is connected so that it can move in a straight line on the LM guide. Accordingly, the support can be moved to a desired position according to the length of the arrow.

[0059] A support is fixedly installed on the LM block, and the user can adjust the forward and rear support positions of the arrow by moving the support. After moving, it can be fixed at the desired position using a fixing bolt, clamp, or locking device.

[0060] LM guides provide high straightness and repeatable positional precision, so they can minimize eccentricity or tilting that may occur when moving the support.

[0061] In addition, a ruler or length indicator may be formed on the LM guide, allowing the user to repeatedly set the same position according to the arrow length.

[0062] If necessary, a lead screw, ball screw, or fine adjustment screw mechanism may be additionally installed to finely adjust the travel distance.

[0063] With the above LM guide moving structure, the user can quickly mount arrows of different lengths and always perform measurements at the same reference position, thereby improving the accuracy and repeatability of straightness measurements.

[0064] 5. Dial gauge measuring section

[0065] The dial gauge measuring unit of the present invention is configured to precisely measure the straightness, degree of bending, and runout of an arrow.

[0066] The dial gauge measuring unit may be configured to include a dial gauge, a gauge support, and a position adjustment unit.

[0067] The dial gauge is installed so that a measuring probe (contact pin) contacts the outer surface of the arrow shaft, and measures the displacement occurring as the arrow rotates in real time.

[0068] The gauge support can be fixed or movably installed on a base and is configured to allow the measurement position to be freely changed. Accordingly, measurements can be taken at any desired location, such as the front, center, or rear of the arrow.

[0069] The position adjustment unit is a device for adjusting the height and forward / backward position of the dial gauge, enabling it to accommodate arrows of various diameters.

[0070] During measurement, the arrow rotates while resting on the bearings of the supports on both sides, and the measuring tip of the dial gauge contacts the surface of the arrow. The straightness or eccentricity of the position can be checked through the difference between the maximum and minimum values ​​displayed on the dial gauge while the arrow rotates 360 degrees.

[0071] If necessary, multiple dial gauges can be installed to measure multiple sections of the arrow simultaneously, allowing for the analysis of the straightness distribution over the entire length.

[0072] In addition, a digital indicator can be used instead of a dial gauge, and the measured values ​​can be displayed or stored electronically.

[0073] The above dial gauge measuring part can quantitatively measure minute bending or eccentricity that is difficult to detect with the naked eye, and can improve the reliability of arrow quality inspection and sorting operations.

[0074] 6. Measurement Method

[0075] The method for measuring the straightness of an arrow according to the present invention is performed in the following steps.

[0076] (1) Arrow loading step

[0077] The arrow to be measured is placed on the bearings of the first support and the second support.

[0078] At this time, the arrow shaft is supported by a bearing and positioned in a state where it can rotate freely.

[0079] (2) Step to adjust the position of the support

[0080] Adjust the support that moves along the LM guide according to the length of the arrow so that the arrow is stably supported.

[0081] After adjusting the position of the support, fix the position using a fixing device.

[0082] (3) Dial gauge position setting step

[0083] Adjust the position so that the measuring tip of the dial gauge contacts the outer surface of the arrow.

[0084] A dial gauge can be placed on the front, center, or rear of the arrow as needed.

[0085] (4) Arrow rotation step

[0086] The user rotates the arrow by hand or uses a rotating device to rotate it 360 degrees.

[0087] During the rotation process, the dial gauge measures minute displacements on the outer surface of the arrow.

[0088] (5) Step to verify measurement value

[0089] Check the maximum and minimum values ​​displayed on the dial gauge while the arrow completes one rotation.

[0090] The eccentricity or straightness error at the corresponding location is calculated through the difference between the maximum and minimum values.

[0091] (6) Repeated measurement step

[0092] While moving the dial gauge position, the front, center, and rear of the arrow are measured sequentially.

[0093] Through this, the straightness distribution for the entire length of the arrow is verified.

[0094] (7) Quality judgment stage

[0095] If the measured eccentricity is within the standard value, it is judged as an acceptable product, and if it exceeds the standard value, it is judged as a rejected product or a product requiring calibration.

[0096] Measurement results can be recorded and stored and utilized for quality control in the manufacturing process or for selecting arrows for competition.

[0097] 7. Straightness measurement

[0098] The straightness measurement of the present invention is a measurement process to determine how much the central axis of the arrow shaft deviates from the ideal straight axis.

[0099] The arrow to be measured rests on the bearings of the supports on both sides and is positioned so that the arrow can rotate freely.

[0100] The measuring element of the dial gauge is set to contact the outer surface of the arrow shaft.

[0101] When the user slowly rotates the arrow 360 degrees, the indicator of the dial gauge moves due to the slight bending or eccentricity of the arrow.

[0102] At this time, the difference between the maximum and minimum values ​​displayed on the dial gauge is measured to calculate the straightness error at that position.

[0103] The straightness error can be calculated by the following formula.

[0104] TIR=Rmax-RminTIR=R_{max}-R_{min}TIR=Rmax-Rmin

[0105] Here,

[0106] TIR: Total Indicator Reading

[0107] Rmax: Maximum measurement value

[0108] Rmin: Minimum measurement value

[0109] am.

[0110] For example, if the dial gauge shows +0.03 mm and -0.02 mm, the total vibration amount (TIR) ​​is 0.05 mm.

[0111] Measurements can be repeated at the front, middle, and rear sections of the arrow, allowing the straightness status to be checked over the entire length of the arrow.

[0112] The smaller the straightness error, the closer the arrow's center axis is to a straight line, improving straight-line flight performance and hit precision.

[0113] Conversely, if the straightness error is large, vibration and deflection may occur during flight, so it may be determined to be subject to screening or correction.

[0114] 8. Concentricity Measurement

[0115] The concentricity measurement of the present invention is a measurement process to verify how well the center of rotation of the arrow shaft coincides with the center of the outer surface.

[0116] The arrow to be measured rests on the bearings of the first and second supports and is supported so that the arrow can rotate freely.

[0117] The measuring element of the dial gauge is positioned to contact the outer surface of the arrow shaft.

[0118] When the user rotates the arrow 360 degrees, the pointer of the dial gauge is displaced according to the eccentricity of the outer surface of the arrow.

[0119] When concentricity is good, the change in the dial gauge needle is very small, whereas when concentricity is poor, the needle moves significantly during rotation.

[0120] The concentricity error can be calculated using the difference between the maximum and minimum values ​​recorded during measurement.

[0121] TIR=Rmax-RminTIR=R_{max}-R_{min}TIR=Rmax-Rmin

[0122] Here,

[0123] TIR: Total Indicator Reading

[0124] Rmax: Maximum measurement value

[0125] Rmin: Minimum measurement value

[0126] am.

[0127] The actual concentricity error can generally be expressed as half the value of the total indicated vibration amount.

[0128] E=TIR2E=\frac{TIR}{2}E=2TIR

[0129] Here,

[0130] E: Concentricity error

[0131] TIR: Total indicated vibration amount

[0132] am.

[0133] For example, if the dial gauge indicates a maximum of +0.04 mm and a minimum of -0.04 mm during rotation, the total indicated vibration is 0.08 mm and the concentricity error is 0.04 mm.

[0134] Measurements can be performed at the front, middle, and rear sections of the arrow, respectively, to verify the concentricity of the arrow over its entire length.

[0135] The smaller the concentricity error, the better the rotational balance of the arrow, and the reduced shaking and vibration during flight can improve hitting precision.

[0136] 9. Arrow Selection

[0137] The present invention relates to a method for measuring the straightness and concentricity of arrows using a measuring device and then sorting the arrows by grade based on the measurement results.

[0138] The arrow to be measured rotates while resting on the bearing of the support, and the straightness and concentricity values ​​are measured using a dial gauge.

[0139] The measured value is compared with a preset allowable threshold value.

[0140] Arrows with straightness and concentricity errors below the standard values ​​are classified as acceptable, while arrows exceeding the standard values ​​may be classified as rejected or subject to correction.

[0141] In addition, it can be selected by classifying into multiple grades based on the measurement values.

[0142] for example,

[0143] Grade A: Straightness error 0.02mm or less

[0144] Grade B: Straightness error greater than 0.02mm ~ 0.05mm or less

[0145] Grade C: Straightness error exceeding 0.05mm

[0146] It can be set as follows.

[0147] Concentricity can also be graded according to the same criteria or separate criteria.

[0148] Selected arrows are stored separately by grade and can be used for competition, training, or correction purposes.

[0149] In addition, the measurement results can be stored in a computer storage device or on a record sheet and can be utilized as data for managing the production history and quality control of arrows.

[0150] 10. Production Line Application

[0151] The arrow straightness and concentricity measuring device according to the present invention can be applied to a production line of an arrow manufacturing process.

[0152] The manufactured arrows are transported along the production line to the measuring section, and at the measuring position, they are automatically or manually placed on the bearings of the support.

[0153] When the arrow is placed at the measurement position, the arrow is rotated by a rotating device or an operator, and a dial gauge or digital measuring device measures the straightness and concentricity of the arrow.

[0154] The measured data is transmitted to the control unit and compared with the set allowable tolerance to determine acceptance.

[0155] Arrows judged to be acceptable are transported to the good product discharge port, and arrows judged to be unacceptable can be automatically sorted to a separate defective product discharge port or re-inspection area.

[0156] In addition, sorting by grade is possible based on measurements, and high-precision competition arrows and general training arrows can be automatically classified.

[0157] Multiple measuring devices can be arranged in series or parallel on the production line, and the overall straightness quality can be inspected by continuously measuring the front, middle, and rear parts of the arrow.

[0158] Measurement results can be stored in a database and used as quality control data in conjunction with production date, production lot number, and measurement history.

Claims

Claim 1 Arrow straightness measuring device comprising first and second arrow supports that rotatably support the arrow and a dial gauge. Claim 2 A device characterized by the above-mentioned support including a bearing. Claim 3 The above support is a device movable on an LM guide. Claim 4 A device capable of adjusting the spacing of supports. Claim 5 A device capable of adjusting the position of a dial gauge. Claim 6 Device for measuring arrow straightness. Claim 7 Arrow concentricity measuring device. Claim 8 Arrow quality sorting device. Claim 9 Archery arrow manufacturing process inspection device. Claim 10 Arrow straightness measuring device comprising the features of any one of the aforementioned claims.

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