Measurement device

The disclosure provides a measurement device for measuring a work piece defining a first circular hole and a second circular hole. The measurement device includes a base, a location member fixed on the base, a fixing pin fixed on the location member, and a measuring pin slidably positioned on the location member. The fixing pin and the measuring pin are configured for being received in the first circular hole and the second circular hole of the work piece, respectively. A diameter of the measuring pin is substantially equal to a standard diameter of the second circular hole minus doubled tolerance. The distance between axes of the fixing pin and the measuring pin is substantially equal to a standard value of the distance between centers of the first and second circular holes of the work piece.

BACKGROUND

1. Technical Field

The present disclosure generally relates to a measurement device, and more particularly, to a device for measuring a distance between axes of two holes in a work piece.

2. Description of Related Art

A work piece, with two holes defined therein, is often assembled with other elements. Accordingly, the distance between the holes is required to fall within a predetermined range to ensure that assembly is successful. Measurement of the distance between the holes in the work piece is thus necessary before assembly.

However, accurate location of the centers of the holes is difficult during measurement, making conventionally used tools impractical. If a projection measuring method or a three-dimensional measurement device is utilized, the measuring process is likely to be protracted and complex.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, an exemplary work piece100is a substantially rectangular housing including a main body10, a first tube portion11, and a second tube portion13. The main body10includes a baseboard (not labeled) and a sidewall (not labeled) extending substantially perpendicular to a surrounding edge of the baseboard. The first tube portion11extends from two sides of the main body10and defines a first circular hole111. The second tube portion13extends to one side of the main body10and defines a second circular hole131. The second circular hole131has a diameter D which is a standard diameter of the second circular hole131. The distance between centers of the first and second circular holes111,131is in a range of L±e, wherein L is a standard value of the distance between the centers of the first and second circular holes111,131, and e is a tolerance therebetween. The distance between the first and second holes111,131is required to be secured in the absolute range of L±e.

Referring toFIG. 3, a measurement device200according to an embodiment includes a base20, a location member30fixed on the base20, a fixing pin40, a measuring assembly50, a fixing block60and an orientation assembly70. The fixing pin40is fixed on the location member30. The measuring assembly50is slidably positioned on the location member30. The fixing block60is fixed on the base20. The orientation assembly70is movably positioned on the fixing block60.

Referring toFIG. 4, the base20is substantially rectangular. The base20defines a plurality of guide holes21and fastener holes (not labeled) therein. The measurement device200further comprises a plurality of fasteners23, two first guiding shafts25, and two second guiding shafts27received in the guide holes21.

The location member30is a substantially T-shaped board and forms two supporting portions31on opposite sides of a bottom end thereof. Each supporting portion31defines a fixing hole311. The location member30further defines a first pin hole33for the fixing pin40, a through hole35, and two second pin holes37adjacent to two sides of the through hole35. The through hole35and the first pin hole33are defined in a central line of the location member30, and a distance therebetween is L. The through hole35and the second pin holes37are defined adjacent to a top portion of the location member30.

The fixing pin40includes a cylindrical main body41, an receiving portion43, and a location flange45between the main body41and the receiving portion43. The main body41has a diameter equaling or exceeding a diameter of the pin hole33of the location member30. Therefore, the main body41is capable of being fixed in the pin hole33of the location member30. The receiving portion43is substantially a cone with a large end connected to the location flange45. The first hole111of the work piece100has a diameter between the minimum diameter and the maximum diameter of the receiving portion43, thus the receiving portion43is capable of being received in the first hole111. The location flange45abuts a portion adjacent to the pin hole33of the location member30to prevent the fixing pin40from sliding relative to the location member30. Alternatively, the location flange45may be omitted if the fixing pin40is molded with the location member30.

The measuring assembly50includes a measuring pin51, a first locking member53, a second locking member55, a fastener57, and two pins59. The measuring pin51is a substantially cylindrical, having a diameter of d, where d=D−2e, that is, the diameter d is substantially equal to D minus doubled e. The diameter of the measuring pin51is substantially equal to a diameter of the through hole35of the location member30, thus the measuring pin51is capable of passing through the through hole35of the location member30. The measuring pin51defines an annular groove511receiving the first locking member53. One end of the measuring pin51defines a fastener hole (not shown) at an end surface for receiving the fastener57. The second locking member55is sleeved on the fastener57such that the first and second locking members53,55are positioned on opposite sides of the location member30. In the illustrated embodiment, the first locking member53is a snap ring, and the second locking member55is a threaded retainer. Two pins59are positioned on opposite sides of the measuring pin51and parallel to each other, and one end of each pin59is fixedly received in one of the second pin holes37. A distance between the pins59exceeds the diameter of the second tube portion13of the work piece100.

The fixing block60includes a substantially rectangular guide portion61and a holding portion63connected to one end of the guide portion61. The holding portion63is substantially perpendicular to the guide portion61. The guide portion61defines a receiving hole611substantially rectangular and two guide holes613communicating with the receiving hole611. The fixing block60defines two holes631passing through both the holding portion63and the guide portion61.

The orientation assembly70includes a pin71, a first latching member73, a resilient member75, a second latching member77, and a fastener79. The pin71includes a shaft portion711and a received portion713formed on an end of the shaft portion711. The shaft portion711has a diameter less than those of the guide holes613. The shaft portion711defines an annular groove715, that receives the first latching member73, and a fastener hole717in the axis direction received in the fastener79. The resilient member75is sleeved on the shaft portion711and received in the receiving hole611of the fixing block60. The second latching member77is threadedly engaged with the fastener79. In the illustrated embodiment, the first latching member73is a snap ring, the resilient member75is a coil spring, and the second latching member77is a threaded retainer. Alternatively, the resilient member75may be a plurality of elastic plates, and the second latching member77a pin.

Also referring toFIG. 5, during assembly of the measurement device200, the location member30is fixed on the base20by the fasteners23and the first guiding shafts25passing through the guide holes21of the base20and the fixing holes311of the location member30. The main body41of the fixing pin40is received in the pin hole33of the location member30. The measuring pin51passes through the location member30, the first locking member53is received in the annular groove511, and the fastener57passes through the second locking member55and is partially received in the fastener hole of the measuring pin51. Therefore, a portion of the measuring pin51between the first and second locking members53,55is capable of sliding relative to the location member30. Each pin59is fixed on the location member30with one end received in one of the second pin holes37.

The fixing block60is fixed on the base20by the fasteners23and the second guiding shafts27passing through the holes631of the fixing block60and the guide holes21. The resilient member75is received in the receiving hole611of the fixing block60. The received portion713of the pin71passes through one guide hole613, the resilient member75, and the other guide hole613in that order. Furthermore, the first latching member73is received in the annular groove715of the pin71. Therefore, opposite ends of the resilient member75resist the inner sidewall of the receiving hole611and the first latching member73. The fastener79passes through the second latching member77and is partially received in the pin71. Thereby, a portion of the pin71between the first and second latching members73,77is capable of sliding relative to the fixing block60. The measurement device200is thus assembled.

Also referring toFIGS. 1 and 6, in use, the work piece100is installed on the measurement device200to be measured. During installation, the fastener79of the orientation assembly70is pulled away from the location member30. The resilient member75is compressed. The work piece100is received between the pin71and the location member30, and the first tube portion11thereof is sleeved on the receiving portion43of the fixing pin40. The pin71is released, such that the received portion713thereof is received in the first tube portion11of the work piece100by the biasing force of the resilient member75. Therefore, the work piece100is fixed by the receiving portion43of the fixing pin40and the received portion713of the pin71, and a central axis of the first tube portion11of the work piece100is aligned with the axes of the fixing pin40and the pin71.

The second tube portion13of the work piece100is capable of swinging between two pins59of the measuring assembly50around the axis of the first tube portion11while the first tube portion11is fixed. The pins59provide initial orientation of the second tube portion13of the work piece100. The fastener57is pulled to slide the measuring pin51towards the second tube portion13of the work piece100. If the measuring pin51can be received in the second tube portion13of the work piece100, it can be concluded that the distance between the axes of the first circular hole111of the first tube portion11and the second circular hole131of the second tube portion13are in a range of L±e, such that the work piece100is acceptable. On the contrary, if the measuring pin51cannot be received in the second tube portion13, it can be concluded that the work piece100is unacceptable.

The measurement device200has a simple structure and is easily manipulated.

Alternatively, the first and second locking members53,55of the measuring assembly50and the first and second latching members73,77of the orientation assembly70can be omitted, with two ends of the resilient member75of the orientation assembly70resisting the inner sidewall of the receiving hole611of the fixing block60. Both the fixing block60and the orientation assembly70can be omitted, and force on the work piece100provides contact with the fixing pin40. The pins59of the measuring assembly50may be omitted, and the initial orientation to the work piece100omitted correspondingly.