200923230 九、發明說明： 【發明所屬之技術領域】 本發明是關於一種鏈條，特別是指一種在鏈片上設置 減重孔之可減輕重量的鏈條。 【先前技術】 參閱圖1、2，以往可減輕重量之鏈條通常包含：數個 串接早το 1，每個串接單元！都包括：兩片内外平行之内鏈 片11、兩片分別位在内鏈片u外側的外鏈片12、兩個左右 間隔地位在内鏈片u間的鏈輥13，以及兩支串接相鄰之鏈 片11、12的鏈軸14。上述内鏈片u皆具有兩個左右間隔 之端部111，以及一位在該等端部丨丨丨間的銜接部丨12，每 個端部111皆具有一供鏈軸14穿過的軸樞孔113，以及一 個自軸樞孔113周緣往另一内鏈片u突出的突柱114，而 該銜接部112除了具有兩條分別位在上方及下方並往内鏈片 11之一圓心連線13弧彎的輪廓面115外，還具有一個界定 出一減重孔10的孔圍繞面15。 其中該孔圍繞面15包括：兩段分別鄰近軸柩孔丨丨3的 第一弧段151，以及兩個銜接在該等第一弧段151間的第二 弧段152，上述第一弧段151分別圍繞一圓心153，並具有 一個鄰近軸樞孔113並位在圓心連線13上的基準點154， 以及兩與第二弧段152接連的端點丨55，前述端點丨54皆位 在兩條垂直於圓心連線13並通過基準點丨54之基準連線工6 間。 而該等外鏈片12亦具有兩個端部丨2丨，以及一個連接 200923230 在端部121間的銜接部122,於銜接部122上亦具有—個減 重孔123，由於該減重孔123的形狀與内鏈片u之減重孔 W相同，不再說明。而該等鏈軸14是包括一段對應鏈片u 12的軸基部141，以及兩段位在軸基部141相反端並突 出於外鏈片12的鉚合部丨42,在該軸基部141及鉚合部 142間界定出一個中空道143，其中該等鉚合部142的厚度 與軸基部142相同。當外力施加在鏈軸14之鉚合部142時 ，前述鉚合部142將向周緣擴散形成一個鉚合突緣144。即 在未鉚合狀態下，該鏈車由14具有兩個厚度相同的鉚合部 142’而在鉚合後該等鉚合部142會向外鏈# 12擴展形成 鉚合突緣144。 外鏈片11、12的減重孔10 習知鏈條雖可藉由内 123’來達到減輕鏈條整體重量的目#，但是在減輕重量纪 部分仍可再加強。而在鏈軸14的設計上，由於該鏈軸卜 之軸基部⑷及鉚合部142的厚度—致，因此，當柳合部 142受到沖壓向外擴展形成鉚合突緣144時，該鉚合突絲 144容易偏斜’而無法均勾擴散在中空道⑷周緣，造· 合品質不穩定。 【發明内容】 主本lx明之主要目的係在提供—種在不影響結構強度的 f月況下it #減輕重量之可減輕重量的鍵條。 本發明可減輕重量的鏈條包含：數個串接單元，每個 串接單元都包括兩片第一桌 乃弟鏈片、兩片弟二鏈片，以及兩支 串接相鄰键片的鏈車由，5 d、甘士 趟釉，至少其中一個第一鏈片具有兩個左 200923230 右間隔且各別具有一供鏈軸穿過之軸樞孔的端部、一個介 於該等端部間的銜接部、一條通過該等軸枢孔之一圓心的 圓心連線，以及兩條分別通過該等圓心並和圓心連線垂直 的圓心垂線。該銜接部具有一個界定出一減重孔的孔圍繞 面，此該孔圍繞面包括兩個各別鄰近軸樞孔的第一段，以 及兩個銜接該等第一段的第二段，每個第一段都具有一位 在圓心連線上的基準點，以及兩個位在該圓^連線之相反 側的鈿點，又5亥第一鏈片更具有兩條分別通過基準點並垂 直於圓錢線之基準线，而該等端點是$超過該基準垂 線地位在相鄰之圓心垂線及基準垂線之間。 本發明的有益功效在於：藉由改變減重孔的形狀，可 以在不影響鏈條結構強度的情況下擴大減重孔的面積，以 達到進一步減輕鏈條重量之目的。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 、下_ δ >考圖式之較佳實施例的詳細說明中，將可清楚 的呈現。 在本發明被詳細描述之前，要注意的是，在以下的說 明内谷中’類似的元件是以相同的編號來表示 參閱圖3、4、5’本發明鏈條之第一較佳實施例包含： 數Γ左右設置之串接單元3。每個串接單元3都包括：兩片 内卜平仃之第一鏈片4、兩個可轉動地位在該等第一鏈片4 1的鏈3 1、兩片分別位在同側之第—鏈片4外侧且部分 重疊的第二鍵片6’以及兩支串接相鄰之第-及第二鏈片4 200923230 、6的鏈軸5。 其中該等第一鏈片4都具有兩個左右間隔之端部41， 以及一個位在端部41間的銜接部42，每個端部41都具有 一個端部圓心411、一個圍繞該端部圓心411的端部輪廓面 412、一個軸枢孔413，以及一個由軸樞孔413周緣往另一 第一鏈片4突出的突柱414。而該第一鏈片4還具有一條連 接該等端部圓心411的圓心連線43、兩條垂直於該圓心連 線43並通過端部圓心411的圓心垂線44，以及兩條設在内 側面上並橫跨端部41及銜接部42的倒角40。 而該銜接部42具有兩個銜接在端部輪廓面4丨2間的銜 接輪廓面421，以及一個界定出—減重孔422的孔圍繞面 45在本只細•例中’ s亥專銜接輪廓面421是往中央弧凹的 凹弧狀。而該減重孔422是對稱地位在圓心連線43之相反 側，該孔圍繞面45包括：兩段分別鄰近相鄰之軸樞孔413 的第一段451，以及兩個銜接在第一段451之上方及下方的 第二段452，其中第-段451呈凹孤狀並圍繞鄰近之端部圓 心411，具有一個落在該圓心連線43上的基準點4兄，以及 兩個为別位在s亥圓心連線43之相反側的端點454，而該第 一鏈片4更具有兩條分別通過基準點453並垂直於圓心連 線43的基準垂線46’而該等端點454位在相鄰之基準垂線 46及圓心垂線44間。本實施例之第二段452是銜接在第一 段451之端點454間，並順著銜接輪廓面42丨之弧彎曲線 弧幫。而該等_ 31是可轉動地純在第m之對應 突柱414間。 8 200923230 參閱圖3、5、6，本實施例之第二鏈片6都具有兩個左 右間隔的端部61’以及-個位在上述端部61 @的銜接部 62，每個端部61都具有—個供鏈軸5穿過的軸樞孔μ卜 而該銜接部62具有一個朝向第一鏈片4的内側面621、— 個外側面622、一個貫穿内、外側面621、622並界定出一 個減重孔623的孔圍繞面63，以及兩條連接在内、外側面 621、622間的凹弧銜接輪廓面62〇，上述減重孔623及孔 圍繞面63的形狀及構造都和第一鏈片4相同，不再贅述， 而孔圍繞面63亦具有兩條彎弧的第—段63丨，以及兩條彎 弧的第二段632。本實施例之第二鏈片6的兩軸樞孔611之 圓心間的節距p假設為12.7mm，本實施例之減重孔623的 第一奴63 1係以軸樞孔611之圓心為圓心的彎弧狀，其半徑 較佳為2.7 mm〜3.3 mm，因此，本實施例該第二鏈片6之孔圍 繞面63到相鄰之軸枢孔611間的最短距離评丨則以 〇·9〜1.5mm為較佳，而該孔圍繞面63到銜接輪廓面62〇間 的最短距離W2則以1.4〜2.0mm為較佳。為設計各種尺寸大 小不一的鏈片，根據上述尺寸大小可推算出 W1/P 0.07〜0.12，乃為較佳的比例設計。又本實施例第一鏈 片4之孔圍繞面45到軸樞孔413以及銜接輪廓面421間的 最紐距離’亦和第二鏈片6相同，不再贅述。 而該銜接部62之内側面621更具有兩個位在對角位置 的第一凹緣625、兩個與上述第一凹緣625鄰接且深度較淺 的第二凹緣626，以及兩個沿著邊緣設置並跨越第一及第二 凹緣625、626的導斜面627，而該外側面622具有兩個對 200923230 應第—凹緣625的第一突緣628，以及兩個對應第二凹緣 626的第—突緣629,上述第一突緣㈣突出的高度大於該 第^—突緣629。 本只靶例之鏈軸5包括一個圍繞一中心軸線設置且介 =第二鏈片6間的軸基部51，以及兩段位在轴基部51相反 端亚突出於第二鏈片6的鉚合部52，在該轴基部Η及鉚合 部52間界定出一個軸向的中空道53，其中該軸基部51具200923230 IX. Description of the Invention: [Technical Field] The present invention relates to a chain, and more particularly to a chain which can reduce the weight by providing a weight reducing hole on the chain. [Prior Art] Referring to Figures 1 and 2, the conventional weight-reducing chain usually consists of: several serial connections το 1, each serial unit! Both include: two inner and outer parallel inner chain pieces 11, two outer outer chain pieces 12 respectively located outside the inner chain piece u, two left and right chain rollers 13 spaced apart between the inner chain pieces u, and two serially connected The chain shaft 14 of the adjacent chain pieces 11, 12. The inner chain pieces u each have two left and right spaced end portions 111, and a connecting portion 丨12 between the end portions, each end portion 111 having an axis through which the chain shaft 14 passes. a pivot hole 113, and a stud 114 protruding from the periphery of the pivot hole 113 toward the other inner link u, and the engaging portion 112 has two centered upper and lower portions and connected to the inner chain piece 11 Outside the contoured surface 115 of the line 13 arc, there is also a hole surrounding surface 15 defining a weight reducing aperture 10. The hole surrounding surface 15 includes: two first arc segments 151 adjacent to the axis bores 3, and two second arc segments 152 coupled between the first arc segments 151, the first arc segments 151 respectively surround a center 153, and has a reference point 154 adjacent to the pivot hole 113 and located on the center line 13 and two end points 丨55 connected to the second arc 152. 6 lines are connected between two reference lines perpendicular to the center line 13 and passing through the reference point 丨54. The outer chain piece 12 also has two end portions 丨2丨, and an connecting portion 122 connecting the end of the end portion 121 of the 200923230. The connecting portion 122 also has a weight reducing hole 123 due to the weight reducing hole. The shape of 123 is the same as that of the weight reducing hole W of the inner chain piece u, and will not be described. The chain shafts 14 are a shaft base portion 141 including a length of the corresponding chain piece u 12, and two rivet portions 丨 42 which are located at opposite ends of the shaft base portion 141 and project from the outer chain piece 12, and are riveted at the shaft base portion 141. A plurality of hollow passages 143 are defined between the portions 142, wherein the thickness of the rivet portions 142 is the same as the shaft base portion 142. When an external force is applied to the caulking portion 142 of the chain shaft 14, the aforementioned caulking portion 142 will diffuse toward the periphery to form a riveting flange 144. That is, in the unsnapped state, the chain car 14 has two riveting portions 142' having the same thickness, and after riveting, the caulking portions 142 are expanded toward the outer chain #12 to form the riveting flanges 144. The weight reducing holes 10 of the outer chain sheets 11, 12, although the inner chain 123' can achieve the weight reduction of the overall weight of the chain by the inner 123', can be further enhanced in the weight reduction portion. On the design of the chain shaft 14, since the thickness of the shaft base portion (4) and the rivet portion 142 of the chain shaft is uniform, when the lyo portion 142 is outwardly expanded by the punch to form the rivet flange 144, the rivet The mating wire 144 is easily deflected' and cannot be uniformly spread on the periphery of the hollow channel (4), resulting in unstable quality. SUMMARY OF THE INVENTION The main purpose of the main body is to provide a key bar that can reduce the weight of the weight loss without affecting the structural strength. The weight-reducing chain of the present invention comprises: a plurality of serially connected units, each of the series-connecting units comprising two pieces of the first table and the second piece, two pieces of the two pieces, and two chains of the adjacent pieces. Car, 5 d, Ganzi glaze, at least one of the first links has two left 200923230 right intervals and each has an end for the shaft pivot through which the chain shaft passes, one at each end An intervening portion, a center line passing through a center of one of the pivot holes, and two center perpendiculars passing through the centers of the centers and perpendicular to the center line. The engaging portion has a hole surrounding surface defining a weight reducing hole, the hole surrounding surface comprising two first segments respectively adjacent to the pivot hole, and two second segments engaging the first segments, each Each of the first segments has a reference point on the line connecting the center line, and two points on the opposite side of the line, and the first chain of 5 hai has two points passing through the reference point respectively. A reference line perpendicular to the round money line, and the end points are greater than the reference vertical line position between the adjacent center line and the reference vertical line. The beneficial effect of the invention is that by changing the shape of the weight reducing hole, the area of the weight reducing hole can be enlarged without affecting the strength of the chain structure, so as to further reduce the weight of the chain. [Embodiment] The foregoing and other technical contents, features and effects of the present invention will be apparent from the detailed description of the preferred embodiments of the present invention. Before the present invention is described in detail, it is noted that in the following description, like elements are referred to by the same reference numerals. Referring to Figures 3, 4, 5, a first preferred embodiment of the chain of the present invention comprises: The tandem unit 3 is set up to the left and right. Each of the series units 3 includes: a first piece 4 of two inner flats, two chains 3 1 which are rotatable in the first chain 4 1 , and two pieces respectively located on the same side a second key piece 6' which is outside and partially overlapped by the chain piece 4, and two chain shafts 5 which are connected in series to the adjacent first and second chain pieces 4 200923230, 6. Wherein the first chain pieces 4 have two left and right spaced ends 41, and an engaging portion 42 located between the ends 41, each end 41 having an end center 411, one surrounding the end An end contour surface 412 of the center 411, a shaft pivot hole 413, and a stud 414 projecting from the periphery of the shaft pivot hole 413 toward the other first link 4. The first chain piece 4 further has a center line 43 connecting the end centers 411, two centered vertical lines 44 perpendicular to the center line 43 and passing through the end center 411, and two inner side surfaces. The chamfer 40 is raised over the end portion 41 and the engaging portion 42. The engaging portion 42 has two engaging contour faces 421 that are connected between the end contour faces 4丨2, and a hole surrounding face 45 defining the weight reducing holes 422 is in the thinner case. The contoured surface 421 is concavely curved toward the central arc. The weight reducing hole 422 is symmetrically positioned on the opposite side of the center line 43. The hole surrounding surface 45 includes: two first segments 451 adjacent to the adjacent pivot holes 413, and two connected to the first segment. The second section 452 above and below the 451, wherein the first section 451 is concavely shaped and surrounds the adjacent end center 411, has a reference point 4 brother falling on the center line 43, and two are different The end point 454 is located on the opposite side of the s-round center line 43, and the first link 4 has two reference vertical lines 46' that pass through the reference point 453 and are perpendicular to the center line 43 and the end points 454 It is located between the adjacent reference vertical line 46 and the center vertical line 44. The second segment 452 of the present embodiment is connected between the end points 454 of the first segment 451 and bends along the arc of the connecting contour surface 42. And these _ 31 are rotatably pure between the corresponding posts 414 of the mth. 8 200923230 Referring to Figures 3, 5 and 6, the second chain piece 6 of the present embodiment has two left and right spaced end portions 61' and - an engaging portion 62 at the end portion 61 @, each end portion 61 Each has a pivot hole for the chain shaft 5 to pass through, and the engaging portion 62 has an inner side surface 621 facing the first chain piece 4, an outer side surface 622, and a through inner and outer side surfaces 621, 622. A hole surrounding surface 63 defining a weight reducing hole 623, and two concave arc engaging contour faces 62 connected between the inner and outer side surfaces 621, 622, the shape and configuration of the weight reducing hole 623 and the hole surrounding surface 63 are both The same as the first link 4, the details are not described again, and the hole surrounding surface 63 also has two curved first segments 63丨 and two curved second segments 632. The pitch p between the centers of the two pivot holes 611 of the second chain piece 6 of the present embodiment is assumed to be 12.7 mm, and the first slave 63 1 of the weight reducing hole 623 of the present embodiment is centered on the pivot hole 611. The radius of the center of the circle is preferably 2.7 mm to 3.3 mm. Therefore, in this embodiment, the shortest distance between the hole surrounding surface 63 of the second chain piece 6 and the adjacent pivot hole 611 is evaluated. 9 to 1.5 mm is preferable, and the shortest distance W2 between the hole surrounding surface 63 and the connecting contour surface 62 is preferably 1.4 to 2.0 mm. In order to design a chain of various sizes, it is possible to derive W1/P 0.07~0.12 according to the above size, which is a preferred ratio design. Further, the maximum distance □ between the hole surrounding surface 45 of the first chain piece 4 of the first chain piece 4 and the pivot hole 413 and the connecting contour surface 421 is also the same as that of the second chain piece 6, and will not be described again. The inner side surface 621 of the engaging portion 62 further has two first concave edges 625 located at diagonal positions, two second concave edges 626 adjacent to the first concave edge 625 and having a shallow depth, and two edges The leading edge is disposed at an edge and spans the leading bevel surface 627 of the first and second recessed edges 625, 626, and the outer side surface 622 has two first flanges 628 of the pair of recesses 625, and two corresponding second recesses The first flange 629 of the rim 626 has a height that protrudes from the first flange (four) is greater than the first flange 629. The chain shaft 5 of the present target embodiment includes a shaft base portion 51 disposed around a central axis and interposed between the second chain pieces 6, and a rivet portion in which the two stages are sub-projected at the opposite ends of the shaft base portion 51 from the second link piece 6. 52. An axial hollow passage 53 is defined between the shaft base portion and the rivet portion 52, wherein the shaft base portion 51 has
有個内％面511，以及—個相距内環面511等距的外環面 而該鉚合部52具有一段和外環面512直線連接的外 衣犬面521、-段自外環突面521往中心、轴線垂直延伸的外 端面522 ’卩及一個自外端面522往内環面川斜伸並界定 出朝向中二迢53之缺環520的鉚合斜面523，上述缺環 52〇之寬度W3大於或等於〇.2mm。 、 > 1圖3 4、7，本實施例第一鏈片4的設計理念是讓 減重孔422沿著銜接輪靡面421以及軸樞孔413的孤度而 。又即圖7中標不斜線的部位，而圖卜2所示之習知内鏈 片11的減重孔10通常不會报大，但如果挖到最大時，由於 其是採用外凸圓弧的設計，即假使如® 7所示之習知内鏈 片11之減重子L 10力口到最大，且假設該外凸圓弧之減重孔 1〇的減重面積為1，則本發明之内凸凹弧的減重孔422之 咸面積可達將近12，即圖7中斜線標示部分的減重面積 佔〇.2’由於本實施例之減重孔422的四個角落若採用銳角 4，應力木中的問題’故本實施例在該減重孔似的四個 角落各別形成—弧圓’藉此改善以上問題。上述減重孔422 10 200923230 與圖1之習知内鏈片u比較，具有4個擴孔區域423，由 於本發明之第—及第二鏈片4、6的重量都較習知者少且 該等擴孔區域423位在第一鏈片4厚度較大的部位，而不 會影響到第—鏈片4的結構強度’故本發明該項設計確實 可在不影響結構強度的情況下’達到進—步減重的目的。 又本實施财_ 5的設計上，主要是在鏈軸5之鉚 合部52上個鉚合斜面523形成該缺環·，上述柳合斜 面523可以在肺5接受鉚合加工時，讓該柳合部μ比較 平均的往外周緣擴散，故本實施例之鏈軸5也可以在不影 響結合強度的情況下，讓㈣5在鉚合後更為均勻，使柳 合的品質更穩定。依發明人實際測試，本發明之缺環52〇 的寬度W3只要大於或等於〇 2mm ’即具有變形均勻之效果 特別說明的是，本發明第—實施例所定義之第—鍵片4 為—般俗稱的内鏈片，第二鏈片6為—般俗稱的外鍵片， 但刖述第-及第二鏈片4、6的定義只是為了方便說明，其 亦可相反的設計，即第―鏈片4亦可為外鏈片，第二鍵片6 亦可為内鏈片。此外，本發明也不以 片4、6上同時設置減重孔422、623為必要，即 中-種鏈片4、6上設置減重孔似、⑵，即可 預期之功效。 參閱圖8,本發明鏈條之第二較佳實施例的構造大致盥 第一實施例相同，其與第一實施例的差別在於：第一及二 鏈片4、6的構造，以下僅舉第二鏈片6作說明，即該第二 200923230 只把Η之第—鏈片6亦包括兩間隔之端部，以及一銜接 部62，每個端部61亦各別具有一轴拖孔6ΐι，而該銜接部 Μ亦具有兩個分別位在上方及下方之銜接輪廓面㈣，以 及個，丨於該等銜接輪靡面62〇間並界定出一減重孔⑶ 的孔圍繞面63，上述孔圍繞面63亦具有兩第一段631 ’以 及兩第二段632 ’上述第—段631是以軸樞孔6U之圓心由 中心的弧f狀。本實施例的特色在於：該等銜接輪廓面62〇 及第二段632皆為平行於圓心連線43的直線。惟在設計上 ’本發明之第二段632只要是直線即可，但第一段631也 可以是直線狀（容後說明）其中第二段632也不以平行於圓心 連線43為必要。 參閲圖9’本發明鏈條之第三較佳實施例亦和第一較佳 實施例類似’不同者僅為第一及第二鏈片4、6之孔圍繞面 心、63的構造’ W 9舉第一鏈片4為例，即該第—鏈片4 之孔圍繞面45亦包括兩個第一段451，以及兩個第二段 452，上述第一段⑸係和基準垂線46重叠之直線，但在 設計上，該等第—⑧451只是是直線即可，並不以和基準 垂線46重疊為必要。 參閱圖10、U，本發明鏈條之第四較佳實施例亦包含 數個串接單元3,每個串接單元都包括有第—鏈片4、第二 鏈片6,以及串接第一及第二鏈片4、6的鏈轴5。本實i 例與第一實施例的差別在於：第一及第二鏈片4、6具有相 同的構造，以第-鏈片4作說明，該第—鏈片4具有兩個 端部41，以及一位在該等端部41間的銜接部42，上述端 12 200923230 部4】具有高度差，故該銜接部42是由其中一個端部μ往 另-個端部傾斜，在該銜接部42上同樣具有一個界定 出Γ減重孔422的關繞面45，此減重孔似的形狀與第 一貫施例相同，不再贅述。 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍’即大凡依本發明中請專利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 .圖1是一種習知可減輕重量之鏈條的局部剖視分解圖 9 圖2是該習知鏈條之一内鏈片的内側視圖； ISJ · 圚， 圖3是本發明鏈條之第—較佳實施例的局部剖視分解 之 —圖4是一内側視圖，單獨顯示該第_較佳實施例 弟—鏈片； 施例之一第 圖5是一立體圖，單獨顯示該第一較佳實 二鏈片； Λ 獨顯示該第 圖6是該第一較佳實施例的内側視圖，單 二鏈片； 施例之第 圖7是一比對圖，主要顯示該第一較佳實 鍵片與習知鏈片之減重關係； 圖 佳實施例； 疋一類似圖4的視圖，顯示本發明鏈條之第 13 200923230 圖9是一類似圖4的視圖，顯示本發明鏈條之第三較 佳實施例； 圖10是本發明鏈條之第四較佳實施例的未完整組合剖 視圖；及 圖11是一立體圖，單獨顯示該第四較佳實施例的第一 鏈片。 14 200923230 * 【主要元件符號說明】 3 串接單元 51 軸基部 31 鏈輥 511 内環面 4 第一鍵片 512 外環面 40 倒角 52 鉚合部 41 端部 520 缺環 411 端部圓心 521 外環突面 412 端部輪廟面 522 外端面 413 轴樞孔 523 鉚合斜面 414 突柱 53 中空道 42 銜接部 6 第二鏈片 421 銜接輪靡面 61 端部 422 減重孑L 611 軸柩孔 423 擴孔區域 62 銜接部 43 圓心連線 620 銜接輪廊面 44 圓心垂線 621 内側面 45 孔圍繞面 622 外側面 451 第一段 623 減重孔 452 第二段 625 第一凹緣 453 基準點 626 第二凹緣 454 端點 627 導斜面 46 基準垂線 628 第一突緣 5 鏈軸 629 第二突緣 15 200923230 63 孔圍繞面 631第一段 632第二段There is an inner surface 511, and an outer annular surface equidistant from the inner annular surface 511, and the staking portion 52 has a garment outer surface 521 which is linearly connected with the outer annular surface 512, and a segment from the outer annular surface 521. An outer end surface 522 ′′ extending perpendicularly to the center and the axis, and a riveting slope 523 extending from the outer end surface 522 toward the inner annular surface and defining a missing ring 520 facing the middle cymbal 53, the missing ring 52 The width W3 is greater than or equal to 〇.2 mm. > 1 Fig. 3 4, 7, the design concept of the first chain piece 4 of the present embodiment is to make the weight reducing hole 422 along the joint rim face 421 and the shaft pivot hole 413. That is, the portion of FIG. 7 which is not marked with a diagonal line, and the weight reducing hole 10 of the conventional inner chain piece 11 shown in FIG. 2 is generally not reported to be large, but if it is the largest, it is designed with a convex arc. That is, if the weight loss L 10 of the conventional inner chain piece 11 as shown in the formula 7 is maximized, and the weight reduction area of the lightening hole 1 该 of the convex arc is assumed to be 1, the inner concave and convex of the present invention The salty area of the arc reducing hole 422 can reach nearly 12, that is, the weight loss area of the slanted line portion in FIG. 7 occupies 〇2. Because the four corners of the weight reducing hole 422 of the embodiment adopt an acute angle of 4, the stress wood The problem in the present invention is such that the present embodiment forms an arc circle at each of the four corners of the weight reduction hole to thereby improve the above problem. The weight reducing hole 422 10 200923230 has four reaming areas 423 as compared with the conventional inner chain u of FIG. 1, since the weight of the first and second chain pieces 4, 6 of the present invention are less than the conventional ones and the weight The reaming area 423 is located at a portion where the thickness of the first link 4 is large, and does not affect the structural strength of the first link 4, so the design of the present invention can be achieved without affecting the structural strength. The purpose of step-by-step weight reduction. Further, in the design of the present invention, the slanting surface 523 is mainly formed on the staking portion 523 of the staking portion 52 of the chain shaft 5, and the slanting slanting surface 523 can be used when the lung 5 receives the staking process. The lyo portion μ is diffused to the outer periphery of the average. Therefore, the chain shaft 5 of the present embodiment can make the (4) 5 more uniform after riveting without affecting the bonding strength, so that the quality of the stalk is more stable. According to the actual test by the inventors, the width W3 of the missing ring 52〇 of the present invention is greater than or equal to 〇2 mm′, that is, the effect of uniform deformation is particularly illustrated, the first key sheet 4 defined by the first embodiment of the present invention is — The commonly-known inner chain piece, the second chain piece 6 is a commonly known foreign key piece, but the definitions of the first and second chain pieces 4, 6 are only for convenience of explanation, and the opposite design, that is, the first The "chain 4" may also be an outer chain piece, and the second key piece 6 may also be an inner chain piece. Further, the present invention is not necessary to provide the weight reducing holes 422, 623 at the same time on the sheets 4, 6, i.e., the weight-reducing holes, (2) are provided on the medium-chains 4, 6, and the desired effect can be obtained. Referring to Fig. 8, the structure of the second preferred embodiment of the chain of the present invention is substantially the same as that of the first embodiment, and the difference from the first embodiment is that the configurations of the first and second links 4, 6 are as follows. The second chain piece 6 is illustrated, that is, the second 200923230 only includes the first piece of the chain piece 6 also including two spaced ends, and an engaging portion 62, each end portion 61 also having a shaft hole hole 6ΐ, The connecting portion Μ also has two connecting contour faces (four) respectively located above and below, and a hole surrounding surface 63 between the connecting rim faces 62 and defining a weight reducing hole (3), The hole surrounding surface 63 also has two first segments 631 ' and two second segments 632'. The first segment 631 is an arc f-shaped from the center of the pivot hole 6U. The feature of this embodiment is that the connecting contour faces 62 〇 and the second segments 632 are straight lines parallel to the center line 43. However, in the design, the second segment 632 of the present invention may be a straight line, but the first segment 631 may also be linear (described later) wherein the second segment 632 is not necessarily parallel to the center line 43. Referring to Fig. 9', the third preferred embodiment of the chain of the present invention is similar to the first preferred embodiment. 'The difference is only the configuration of the holes of the first and second links 4, 6 around the face center, 63'. 9 is an example of the first chain piece 4, that is, the hole surrounding surface 45 of the first chain piece 4 also includes two first segments 451, and two second segments 452, the first segment (5) overlaps with the reference vertical line 46. The straight line, but in terms of design, the -8451 is only a straight line, and it is not necessary to overlap with the reference vertical line 46. Referring to FIG. 10 and U, the fourth preferred embodiment of the chain of the present invention also includes a plurality of serial units 3, each of which includes a first link 4, a second link 6, and a serial connection. And the chain shaft 5 of the second chain pieces 4, 6. The difference between the first embodiment and the first embodiment is that the first and second links 4, 6 have the same configuration, and the first link 4 has two end portions 41. And a connecting portion 42 between the end portions 41, wherein the end portion 12200923230 portion 4 has a height difference, so the engaging portion 42 is inclined from one end portion μ to the other end portion at the engaging portion. 42 also has a closing surface 45 defining a weight reducing hole 422. The shape of the weight reducing hole is the same as that of the first embodiment, and will not be described again. However, the above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto. All remain within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial cross-sectional exploded view of a conventional weight-reducing chain. Figure 2 is an internal side view of an inner chain of one of the conventional chains; ISJ · 圚, Figure 3 is the present invention The section of the chain - a partial cross-sectional view of the preferred embodiment - Fig. 4 is an inner side view showing the first embodiment of the preferred embodiment - the chain piece; one of the embodiments is a perspective view, which is shown separately The first preferred second two-stranded piece; 独 alone shows that FIG. 6 is an inner side view of the first preferred embodiment, a single two-chain piece; FIG. 7 of the embodiment is an alignment diagram, mainly showing the first The weight reduction relationship between the preferred real bond and the conventional link; Fig. 1 is a view similar to Fig. 4, showing the 13th of the chain of the present invention 200923230. Fig. 9 is a view similar to Fig. 4, showing the chain of the present invention. 3 is a cross-sectional view of an incomplete assembly of a fourth preferred embodiment of the chain of the present invention; and FIG. 11 is a perspective view showing the first link of the fourth preferred embodiment separately. 14 200923230 * [Main component symbol description] 3 Casing unit 51 Shaft base 31 Chain roller 511 Inner ring surface 4 First key piece 512 Outer ring surface 40 Chamfer 52 Riveting part 41 End part 520 Missing ring 411 End center 521 Outer ring face 412 End wheel face 522 Outer end face 413 Axis pivot hole 523 Riveted bevel 414 Bump 53 Hollow path 42 Engagement part 6 Second link 421 Engagement rim face 61 End 422 Weight loss 孑 L 611 Axis Pupil 423 Reaming area 62 Engagement 43 Center line 620 Engagement deck 44 Center line 621 Inner side 45 Hole surrounding surface 622 Outer side 451 First section 623 Weight loss hole 452 Second section 625 First concave edge 453 Reference Point 626 second concave edge 454 end point 627 leading bevel 46 reference vertical line 628 first flange 5 chain axis 629 second flange 15 200923230 63 hole surrounding surface 631 first segment 632 second segment